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  • securing a webservice for use from a custom iphone app only

    - by mme
    I want to create an iphone application which consists of two parts: The app itself and a server side component. On a users request, the app sends data to the server which is to be handled by human operators. To prevent abuse from an iphone app user, the id of the iphone is sent along with the request, and the operators can blacklist pranksters to deny their iphone access to the service. So far so good. Now the problem is: Someone could easily discover the address of the serverside component, and write a script to send bogus requests, using multiple IP addresses etc. So my question is: how can I defend myself against this? Captchas to protect against scripted attacks or requiring the user to register himself are not an option for this particular application. If I had control of the download, I would associate a unique ID with each downloaded app, but obviously this is not an option with the appstore. What would be your approach to make the server side part more secure?

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  • Why is using a Non-Random IV with CBC Mode a vulnerability?

    - by The Rook
    I understand the purpose of an IV. Specifically in CBC mode this insures that the first block of of 2 messages encrypted with the same key will never be identical. But why is it a vulnerability if the IV's are sequential? According to CWE-329 NON-Random IV's allow for the possibility of a dictionary attack. I know that in practice protocols like WEP make no effort to hide the IV. If the attacker has the IV and a cipher text message then this opens the door for a dictionary attack against the key. I don't see how a random iv changes this. (I know the attacks against wep are more complex than this.) What security advantage does a randomized iv have? Is this still a problem with an "Ideal Block Cipher"? (A perfectly secure block cipher with no possible weaknesses.)

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  • Using directory traversal attack to execute commands

    - by gAMBOOKa
    Is there a way to execute commands using directory traversal attacks? For instance, I access a server's etc/passwd file like this http://server.com/..%01/..%01/..%01//etc/passwd Is there a way to run a command instead? Like... http://server.com/..%01/..%01/..%01//ls ..... and get an output? EDIT: To be clear here, I've found the vuln in our company's server. I'm looking to raise the risk level (or bonus points for me) by proving that it may give an attacker complete access to the system

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  • When open-sourcing a live Rails app, is it dangerous to leave the session key secret in source contr

    - by rspeicher
    I've got a Rails app that's been running live for some time, and I'm planning to open source it in the near future. I'm wondering how dangerous it is to leave the session key store secret in source control while the app is live. If it's dangerous, how do people usually handle this problem? I'd guess that it's easiest to just move the string to a text file that's ignored by the SCM, and read it in later. Just for clarity, I'm talking about this: # Your secret key for verifying cookie session data integrity. # If you change this key, all old sessions will become invalid! # Make sure the secret is at least 30 characters and all random, # no regular words or you'll be exposed to dictionary attacks. ActionController::Base.session = { :key => '_application_session', :secret => '(long, unique string)' } And while we're on the subject, is there anything else in a default Rails app that should be protected when open sourcing a live app?

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  • mysqldb python escaping ? or %s?

    - by asldkncvas
    Dear Everyone, I am currently using mysqldb. What is the correct way to escape strings in mysqldb arguments? Note that E = lambda x: x.encode('utf-8') 1) so my connection is set with charset='utf8'. These are the errors I am getting for these arguments: w1, w2 = u'??', u'??' 1) self.cur.execute("SELECT dist FROM distance WHERE w1=? AND w2=?", (E(w1), E(w2))) ret = self.cur.execute("SELECT dist FROM distance WHERE w1=? AND w2=?", (E(w1), E(w2)) ) File "build/bdist.linux-i686/egg/MySQLdb/cursors.py", line 158, in execute TypeError: not all arguments converted during string formatting 2) self.cur.execute("SELECT dist FROM distance WHERE w1=%s AND w2=%s", (E(w1), E(w2))) This works fine, but when w1 or w2 has \ inside, then the escaping obviously failed. I personally know that %s is not a good method to pass in arguemnts due to injection attacks etc.

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  • Today's Links (6/20/2011)

    - by Bob Rhubart
    Why your security sucks | Eric Knorr A conversation with InfoWorld security expert Roger Grimes reveals why the latest burst of attacks is just business as usual. JDev 11g R2 - ADF BC Dependency Diagram Feature | Andrejus Baranovskis Oracle ACE Director Andrejus Baranovkis continues his exploration of JDeveloper 11g R2. Mobile Apps Put the Web in Their Rear-view Mirror | Charles Newark-French "Our analysis shows that, for the first time ever, daily time spent in mobile apps surpasses desktop and mobile web consumption," says Newark-French. "This stat is even more remarkable if you consider that it took less than three years for native mobile apps to achieve this level of usage, driven primarily by the popularity of iOS and Android platforms." Vivek Kundra, a public servant who gets stuff done | Craig Newmark Craigslist founder Craig Newmark bids farewell to the nation's first CIO. Weblogic, QBrowser and topics | Eric Elzinga Elzinga says: "Besides using the Weblogic Console to add subscribers to our topics we can also use QBrowser to browse queues and topics on your Weblogic Server." Java EE talks at JAX Conf | Arun Gupta Arun Gupta shares links to several Java EE presentations taking place at this week's Jax Conference in San Jose, CA. Development gotchas and silver bullets | Andy Mulholland Mulholland explains why "Software development has to change to fit with new business practices!" Oracle is Proud Sponsor of Gartner Security and Risk Management Summit 2011 | Troy Kitch Oracle will have a very strong presence at this year’s Gartner Security and Risk Management Summit 2011 in Washington D.C., June 20-23. Database Web Service using Toplink DB Provider | Vishal Jain "With JDeveloper 11gR2 you can now create database based web services using JAX-WS Provider," says Jain. Sample Chapter: A Fusion Applications Technical Overview An excerpt from "Managing Oracle Fusion Applications" by Richard Bingham, published by Oracle Press, May 2011. White Paper: Oracle Optimized Solution for Enterprise Cloud Infrastructure This paper provides recommendations and best practices for optimizing virtualization infrastructures when deploying the Oracle Enterprise Cloud Infrastructure. White paper: Oracle Optimized Solution for Lifecycle Content Management Authors Donna Harland and Nick Klosk illustrate how Oracle Enterprise Content Management Suite and Oracle’s Sun Storage Archive Manager work Oracle’s Sun hardware. Bay Area Coherence Special Interest Group Date: Thursday, July 21, 2011 Time: 4:30pm - 8:15pm ET - Note that Parking at 475 Sansome Closes at 8:30pm Location: Oracle Office,475 Sansome Street, San Francisco, CA Google Map Speakers: Chris Akker, Solutions Engineer, F5 Paul Cleary, Application Architect, Oracle Alexey Ragozin, Independent Consultant Brian Oliver, Oracle

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  • What do you do when a client requires Rich Text Editing on their website?

    - by George Stocker
    As we all know by now, XSS attacks are dangerous and really easy to pull off. Various frameworks make it easy to encode HTML, like ASP.NET MVC does: <%= Html.Encode("string"); %> But what happens when your client requires that they be able to upload their content directly from a Microsoft Word document? Here's the scenario: People can copy and paste content from Microsoft word into a WYSIWYG editor (in this case tinyMCE), and then that information is posted to a web page. The website is public, but only members of that organization will have access to post information to a webpage. What is the best way to handle this requirement? Currently there is no checking done on what the client posts (since only 'trusted' users can post), but I'm not particularly happy with that and would like to lock it down further in case an account is hacked. The platform in question is ASP.NET MVC. The only conceptual method that I'm aware of that meets these requirements is to whitelist HTML tags and let those pass through. Is there another way? If not, is the best way to let them store it in the Database in any form, but only display it properly encoded and stripped of bad tags? NB: The questions differ in that he only assumes there's one way. I'm also asking the following questions: 1. Is there a better way that doesn't rely on HTML Whitelists? 2. Is there a better way that relies on a different view engine? 3. Is there a WYSIWYG editor that includes the ability to whitelist on the fly? 4. Should I even worry about this since it will only be for 'private posting' (Much in the same way that a private blog allows HTML From the author, but since only he can post, it's not an issue)? Edit #2: If suggesting a WYSIWYG editor, it must be free (as in speech, or as in beer). Update: All of the suggestions thus far revolve around a specific Rich Text Editor to use: Only provide an editor as a suggestion if it allows for sanitization of HTML tags; and it fulfills the requirement of accepting pasted documents from a WYSIWYG Editor like Microsoft Word. There are three methods that I know of: 1. Not allow HTML. 2. Allow HTML, but sanitize it 3. Find a Rich Text Editor that sanitizes and allows HTML. The previous questions remain (1-4 above). Related Question Preventing Cross Site Scripting (XSS)

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  • Happy New Year! Upcoming Events in January 2011

    - by mandy.ho
    Oracle Database kicks off the New Year at the following events during the month of January. Hope to see you there and please send in your pictures and feedback! Jan 20, 2011 - San Francisco, CA LinkShare Symposium West 2011 Oracle is a proud Gold Sponsor at the LinkShare Symposium West 2011 January 20 in San Francisco, California. Year after year LinkShare has been bringing their network the opportunity to come to life. At the LinkShare Symposium online performance marketing leaders meet to optimize face-to-face during a full day of networking. Learn more by attending Oracle Breakout Session, "Omni - Channel Retailing, What is possible now?" on Thursday, January 20, 11:15 a.m. - 12:00 noon, Grand Ballroom. http://eventreg.oracle.com/webapps/events/ns/EventsDetail.jsp?p_eventId=128306&src=6954634&src=6954634&Act=397 Jan 24, 2011 - Cincinnati, OH Greater Cincinnati Oracle User Group Meeting "Tom Kyte Day" - Featuring a day of sessions presented by Senior Technical Architect, Tom Kyte. Sessions include "Top 10, no 11, new features of Oracle Database 11g Release 2" and "What do I really need to know when upgrading", plus more. http://www.gcoug.org/ Jan 25, 2011 - Vancouver, British Columbia Oracle Security Solutions Forum Featuring a Special Keynote Presentation from Tom Kyte - Complete Database Security Join us at this half-day event; Oracle Database Security Solutions: Complete Information Security. Learn how Oracle Database Security solutions help you: • Prevent external threats like SQL injection attacks from reaching your databases • Transparently encrypt application data without application changes • Prevent privileged database users and administrators from accessing data • Use native database auditing to monitor and report on database activity • Mask production data for safe use in nonproduction environments http://eventreg.oracle.com/webapps/events/ns/EventsDetail.jsp?p_eventId=126974&src=6958351&src=6958351&Act=97 Jan 26, 2011 - Halifax, Nova Scotia Oracle Database Security Technology Day Exclusive Seminar on Complete Information Security with Oracle Database 11g The amount of digital data within organizations is growing at unprecedented rates, as is the value of that data and the challenges of safeguarding it. Yet most IT security programs fail to address database security--specifically, insecure applications and privileged users. So how can you protect your mission-critical information? Avoid risky third-party solutions? Defend against security breaches and compliance violations? And resist costly new infrastructure investments? Join us at this half-day seminar, Oracle Database Security Solutions: Complete Information Security, to find out http://eventreg.oracle.com/webapps/events/ns/EventsDetail.jsp?p_eventId=126269&src=6958351&src=6958351&Act=93

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  • Are SQL Injection vulnerabilities in a PHP application acceptable if mod_security is enabled?

    - by Austin Smith
    I've been asked to audit a PHP application. No framework, no router, no model. Pure PHP. Few shared functions. HTML, CSS, and JS all mixed together. I've discovered numerous places where SQL injection would be easily possible. There are other problems with the application (XSS vulnerabilities, rampant inline CSS, code copy-pasted everywhere) but this is the biggest. Sometimes they escape inputs, not using a prepared query or even mysql_real_escape_string(), mind you, but using addslashes(). Often, though, their queries look exactly like this (pasted from their code but with columns and variable names changed): $user = mysql_query("select * from profile where profile_id='".$_REQUEST["profile_id"]."'"); The developers in question claimed that they were unable to hack their application. I tried, and found mod_security to be enabled, resulting in HTTP 406 for some obvious SQL injection attacks. I believe there to be sophisticated workarounds for mod_security, but I don't have time to chase them down. They claim that this is a "conceptual" matter and not a "practical" one since the application can't easily be hacked. Their internal auditor agreed that there were problems, but emphasized the conceptual nature of the issues. They also use this conceptual/practical argument to defend against inline CSS and JS, absence of code organization, XSS vulnerabilities, and massive amounts of repetition. My client (rightly so, perhaps) just wants this to go away so they can launch their product. The site works. You can log in, do what you need to do, and things are visibly functional, if slow. SQL Injection would indeed be hard to do, given mod_security. Further, their talk of "conceptual vs. practical" is rhetorically brilliant, considering that my client doesn't understand web application security. I worry that they've succeeded in making me sound like an angry puritan. In many ways, this is a problem of politics, not technology, but I am at a loss. As a developer, I want to tell them to toss the whole project and start over with a new team, but I face a strong defense from the team that built it and a client who really needs to ship their product. Is my position here too harsh? Even if they fix the SQL Injection and XSS problems can I ever endorse the release of an unmaintainable tangle of spaghetti code?

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  • Ideas for attack damage algorithm (language irrelevant)

    - by Dillon
    I am working on a game and I need ideas for the damage that will be done to the enemy when your player attacks. The total amount of health that the enemy has is called enemyHealth, and has a value of 1000. You start off with a weapon that does 40 points of damage (may be changed.) The player has an attack stat that you can increase, called playerAttack. This value starts off at 1, and has a possible max value of 100 after you level it up many times and make it farther into the game. The amount of damage that the weapon does is cut and dry, and subtracts 40 points from the total 1000 points of health every time the enemy is hit. But what the playerAttack does is add to that value with a percentage. Here is the algorithm I have now. (I've taken out all of the gui, classes, etc. and given the variables very forward names) double totalDamage = weaponDamage + (weaponDamage*(playerAttack*.05)) enemyHealth -= (int)totalDamage; This seemed to work great for the most part. So I statrted testing some values... //enemyHealth ALWAYS starts at 1000 weaponDamage = 50; playerAttack = 30; If I set these values, the amount of damage done on the enemy is 125. Seemed like a good number, so I wanted to see what would happen if the players attack was maxed out, but with the weakest starting weapon. weaponDamage = 50; playerAttack = 100; the totalDamage ends up being 300, which would kill an enemy in just a few hits. Even with your attack that high, I wouldn't want the weakest weapon to be able to kill the enemy that fast. I thought about adding defense, but I feel the game will lose consistency and become unbalanced in the long run. Possibly a well designed algorithm for a weapon decrease modifier would work for lower level weapons or something like that. Just need a break from trying to figure out the best way to go about this, and maybe someone that has experience with games and keeping the leveling consistent could give me some ideas/pointers.

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  • Database Security: The First Step in Pre-Emptive Data Leak Prevention

    - by roxana.bradescu
    With WikiLeaks raising awareness around information leaks and the harm they can cause, many organization are taking stock of their own information leak protection (ILP) strategies in 2011. A report by IDC on data leak prevention stated: Increasing database security is one of the most efficient and cost-effective measures an organization can take to prevent data leaks. By utilizing the data protection, access control, account management, encryption, log management, and other security controls inherent in the database management system, entities can institute first-level control over the widest range of protected information. As a central repository for unstructured data, which is growing at leaps and bounds, the database should be the first layer providing information leakage protection. Unfortunately, most organizations are not taking sufficient steps to protect their databases according to a survey of the Independent Oracle User Group. For example, any operating system administrator or database administrator can access the all the data stored in the database in most organizations. Without any kind of auditing or monitoring. And it's not just administrators, database users can typically access the database with ad-hoc query tools from their desktop and by-pass any application level controls. Despite numerous regulations calling for controls to limit the powers of insiders, most organizations still put too many privileges in the hands of their employees. Time and time again these excess privileges have backfired. Internal agents were implicated in almost half of data breaches according to the Verizon Data Breach Investigations Report and the rate is rising. Hackers also took advantage of these excess privileges very successfully using stolen credentials and SQL injection attacks. But back to the insiders. Who are these insiders and why do they do it? In 2002, the U.S. Secret Service (USSS) behavioral psychologists and CERT information security experts formed the Insider Threat Study team to examine insider threat cases that occurred in US critical infrastructure sectors, and examined them from both a technical and a behavioral perspective. A series of fascinating reports has been published as a result of this work. You can learn more by watching the ISSA Insider Threat Web Conference. So as your organization starts to look at data leak prevention over the coming year, start off by protecting your data at the source - your databases. IDC went on to say: Any enterprise looking to improve its competitiveness, regulatory compliance, and overall data security should consider Oracle's offerings, not only because of their database management capabilities but also because they provide tools that are the first layer of information leak prevention. Learn more about Oracle Database Security solutions and get the whitepapers, demos, tutorials, and more that you need to protect data privacy from internal and external threats.

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  • RPG Monster-Area, Spawn, Loot table Design

    - by daemonfire300
    I currently struggle with creating the database structure for my RPG. I got so far: tables: area (id) monster (id, area.id, monster.id, hp, attack, defense, name) item (id, some other values) loot (id = monster.id, item = item.id, chance) spawn (id = area.id, monster = monster.id, count) It is a browser-based game like e.g. Castle Age. The player can move from area to area. If a player enters an area the system spawns, based on the area.id and using the spawn table data, new monsters into the monster table. If a player kills a monster, the system picks the monster.id looks up the items via the the loot table and adds those items to the player's inventory. First, is this smart? Second, I need some kind of "monster_instance"-table and "area_instance"-table, since each player enters his very own "area" and does damage to his very own "monsters". Another approach would be adding the / a player.id to the monster table, so each monster spawned, has it's own "player", but I still need to assign them to an area, and I think this would overload the monster table if I put in the player.id and the area.id into the monster table. What are your thoughts? Temporary Solution monster (id, attackDamage, defense, hp, exp, etc.) monster_instance (id, player.id, area_instance.id, hp, attackDamage, defense, monster.id, etc.) area (id, name, area.id access, restriction) area_instance (id, area.id, last_visited) spawn (id, area.id, monster.id) loot (id, monster.id, chance, amount, ?area.id?) An example system-flow would be: Player enters area 1: system creates area_instance of type area.id = 1 and sets player.location to area.id = 1 If Player wants to battle monsters in the current area: system fetches all spawn entries matching area.id == player.location and creates a new monster_instance for each spawn by fetching the according monster-base data from table monster. If a monster is fetched more than once it may be cached. If Player actually attacks a monster: system updates the according monster_instance, if monster dies the instance if removed after creating the loot If Player leaves the area: area_instance.last_visited is set to NOW(), if player doesn't return to data area within a certain amount of time area_instance including all its monster_instances are deleted.

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  • Check if an object is facing another based on angles

    - by Isaiah
    I already have something that calculates the bearing angle to get one object to face another. You give it the positions and it returns the angle to get one to face the other. Now I need to figure out how tell if on object is facing toward another object within a specified field and I can't find any information about how to do this. The objects are obj1 and obj2. Their angles are at obj1.angle and obj2.angle. Their vectors are at obj1.pos and obj2.pos. It's in the format [x,y]. The angle to have one face directly at another is found with direction(obj1.pos,obj2.pos). I want to set the function up like this: isfacing(obj1,obj2,area){...} and return true/false depending if it's in the specified field area to the angle to directly see it. I've got a base like this: var isfacing = function (obj1,obj2,area){ var toface = direction(obj1.pos,obj2.pos); if(toface+area >= obj1.angle && ob1.angle >= toface-area){ return true; } return false; } But my problem is that the angles are in 360 degrees, never above 360 and never below 0. How can I account for that in this? If the first object's angle is say at 0 and say I subtract a field area of 20 or so. It'll check if it's less than -20! If I fix the -20 it becomes 340 but x < 340 isn't what I want, I'd have to x 340 in that case. Is there someone out there with more sleep than I that can help a new dev pulling an all-nighter just to get enemies to know if they're attacking in the right direction? I hope I'm making this harder than it seems. I'd just make them always face the main char if the producer didn't want attacks from behind to work while blocking. In which case I'll need the function above anyways. I've tried to give as much info as I can think would help. Also this is in 2d.

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  • Server-infrastructure recommendations

    - by Tim van Elsloo
    Here's the thing: I need a cheap, fast, reliable infrastructure that can dynamically scale (like Amazon S3: cloud-storage). I'm thinking of 3 different type of 'servers'. Application-server Should be able to run CentOS (or another light Linux-distr.) Should be able to run Apache Should be able to run PHP Should be able to run GD (so it does rely on it's cpu). Should be extremely reliable and fast. Database-server Should be able to run MySQL Should be able to... well, do nothing else :P. Should be extremely reliable and fast. Storage-server Should be able to run some kind of file-transfer-deamon (like FTP, CouchDB, etc.) Should be able to do nothing else. Should be extremely reliable and fast. So technically, by transferring all static data to 2 different servers/services, the application-server can totally focus on the webpages. My questions: What services do you recommend? Which is cheaper, faster and more reliable: using my own server, or using some cloud-storage/cloud-computing-service (like Amazon S3, CloudFiles, etc.)? How can I prevent bandwidth abuse (such as dos-attacks causing the bill to be extremely high)? What's the difference between "including CDN" and "excluding CDN"? It seems the price doesn't differ at CloudFiles? Do you have to pay "including CDN" + "excluding CDN" when you decide to enable the delivery-network? Or have you only got to pay "including CDN"? Should I use my own nameserver too or can I use my domain-hoster's nameservers? What are the minimum software specifications of a nameserver. Can I write some software myself? Does anyone have a good protocol-description? I hope you can answer my questions. Answers I shouldn't write my own nameserver-software. Instead, I should use something like bind. (http://osspro.com/2010/05/04/linux-create-your-own-domain-name-server-dns/).

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  • Help with Strategy-game AI

    - by f20k
    Hi, I am developing a strategy-game AI (think: Final Fantasy Tactics), and I am having trouble coming up for the design of the AI. My main problem is determining which is the optimal thing for it to do. First let me describe the priority of what action I would like the AI to take: Kill nearest player unit Fulfill primary directive (kill all player units, kill target unit, survive for x turns) Heal ally unit / cast buffer Now the AI can do the following in its turn: Move - {Attack / Ability / Item} (either attack or ability or item) {Attack / Ability / Item} - Move Move closer (if targets not in range) {Attack / Ability / Item} (if move not available) Notes Abilities have various ranges / effects / costs / effects. Each ai unit has maybe 5-10 abilities to choose from. The AI will prioritize killing over safety unless its directive is to survive for x turns. It also doesn't care about ability cost much. While a player may want to save a big spell for later, the AI will most likely use it asap. Movement is on a (hex) grid num of player units: 3-6 num of ai units: 3-7 or more. Probably max 10. AI and player take turns controlling ONE unit, instead of all at the same time. Platform is Android (if program doesnt respond after some time, there will be a popup saying to Force Quit or Wait - which looks really bad!). Now comes the questions: The best ability to use would obviously be the one that hits the most targets for the most damage. But since each ability has different ranges, I won't know if they are in range without exploring each possible place I can move to. One solution would be to go through each possible places to move to, determine the optimal attack at that location - which gives me a list of optimal moves for each location. Then choose the optimal out of the list and execute it. But this will take a lot of CPU time. Is there a better solution? My current idea is to move as close as possible towards the closest, largest group of people, and determine the optimal attack/ability from there. I think this would be a lot less work for the CPU and still allow for wide-range attacks. Its sub-optimal but the AI will still seem 'smart'. Other notes/questions: Am I over-thinking/over-complicating it? Better solution? I am open to all sorts of suggestions I have taken a look at the spell-casting question, but it doesn't take into account the movement - so perhaps use that algo for each possible move location? The top answer mentioned it wasn't great for area-of-effect and group fights - so maybe requires more tweaking? Please, if you mention a graph/tree, let me know basically how to use it. E.g. Node means ability, level corresponds to damage, then search for the deepest node.

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  • Understanding the levels of computing

    - by RParadox
    Sorry, for my confused question. I'm looking for some pointers. Up to now I have been working mostly with Java and Python on the application layer and I have only a vague understanding of operating systems and hardware. I want to understand much more about the lower levels of computing, but it gets really overwhelming somehow. At university I took a class about microprogramming, i.e. how processors get hard-wired to implement the ASM codes. Up to now I always thought I wouldn't get more done if learned more about the "low level". One question I have is: how is it even possible that hardware gets hidden almost completely from the developer? Is it accurate to say that the operating system is a software layer for the hardware? One small example: in programming I have never come across the need to understand what L2 or L3 Cache is. For the typical business application environment one almost never needs to understand assembler and the lower levels of computing, because nowadays there is a technology stack for almost anything. I guess the whole point of these lower levels is to provide an interface to higher levels. On the other hand I wonder how much influence the lower levels can have, for example this whole graphics computing thing. So, on the other hand, there is this theoretical computer science branch, which works on abstract computing models. However, I also rarely encountered situations, where I found it helpful thinking in the categories of complexity models, proof verification, etc. I sort of know, that there is a complexity class called NP, and that they are kind of impossible to solve for a big number of N. What I'm missing is a reference for a framework to think about these things. It seems to me, that there all kinds of different camps, who rarely interact. The last few weeks I have been reading about security issues. Here somehow, much of the different layers come together. Attacks and exploits almost always occur on the lower level, so in this case it is necessary to learn about the details of the OSI layers, the inner workings of an OS, etc.

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  • Why does ping flooding a domain name freezes and not a direct ip address

    - by CYREX
    I am wondering why, when ping flooding a domain, the ping flood freezes after a couple of seconds then continues and this freeze, unfreeze continues until i stop the ping flood. When i do the same using the ip it does not freeze. NEVER. i did for example sudo ping -f IP (It does not freeze) then i did sudo ping -f DomainName (It freezes after a couple of seconds) Why does ping flooding an IP not freezes and ping flooding the same place using the domain name does freeze. EDIT - What i mean about freezing is that the behavior of the ping flood should send a ping and create a dot (.) for each ping but also remove each dot (.) after receiving the echo request. Looks something like this: .......... <-- This means you just send 10 ping requests. If the requests are answer, for each request answer a dot is removed. The freeze happens when this is sending or receiving. The dots will stay there frozen, like is not receiving or sending any packets. For the PING FLOOD. I do not mean in the evil way of flooding a place, i mean in the testing way. To test the performance/speed of the request send and answered of the ping requests. If you send a ping flood to google's IP for about 10 seconds you would have send about 1000 packets.but if you do it to google's domain name (google.com) it will create the freeze am talking about. IMPORTANT - Do not confuse with flooding a site with ping of death attacks.

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  • Amazon Ec2: Problem In Setting up FTP Server

    - by Muntasir
    after setting up My vsFtp Server ON Ec2 i am facing problem , my client is Filezilla and i am getting this error Response: 230 Login successful. Command: OPTS UTF8 ON Response: 200 Always in UTF8 mode. Status: Connected Status: Retrieving directory listing... Command: PWD Response: 257 "/" Command: TYPE I Response: 200 Switching to Binary mode. Command: PASV Response: 500 OOPS: invalid pasv_address Command: PORT 10,130,8,44,240,50 Response: 500 OOPS: priv_sock_get_cmd Error: Failed to retrieve directory listing Error: Connection closed by server this is the current setting in my vsftpd.conf #nopriv_user=ftpsecure #async_abor_enable=YES # ASCII mangling is a horrible feature of the protocol. #ascii_upload_enable=YES #ascii_download_enable=YES # You may specify a file of disallowed anonymous e-mail addresses. Apparently # useful for combatting certain DoS attacks. #deny_email_enable=YES # (default follows) #banned_email_file=/etc/vsftpd/banned_emails # chroot_local_user=YES #chroot_list_enable=YES # (default follows) #chroot_list_file=/etc/vsftpd/chroot_list GNU nano 2.0.6 File: /etc/vsftpd/vsftpd.conf # #ls_recurse_enable=YES # # When "listen" directive is enabled, vsftpd runs in standalone mode and # listens on IPv4 sockets. This directive cannot be used in conjunction # with the listen_ipv6 directive. listen=YES # # This directive enables listening on IPv6 sockets. To listen on IPv4 and IPv6 # sockets, you must run two copies of vsftpd with two configuration files. # Make sure, that one of the listen options is commented !! #listen_ipv6=YES pam_service_name=vsftpd userlist_enable=YES tcp_wrappers=YES pasv_enable=YES pasv_min_port=2345 pasv_max_port=2355 listen_port=1024 pasv_address=ec2-xxxxxxx.compute-1.amazonaws.com pasv_promiscuous=YES Note: i have already open those port in security group i mean listen port, min max if someone shows me how to fix this i will be very greatful thanks

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  • Why do I have untrusted certificates for Google, Yahoo, Mozilla and others?

    - by jackweirdy
    In the HTTPS/SSL section of chrome://chrome/settings, I see the following: What does this mean, and is there something wrong? I have a basic understanding of SSL/TLS - I'm not claiming to be completely familiar, but I'm fairly confident I know my way around it - but I don't understand why I have certificates installed on my machine specifically for these sites. From my understanding, I should have the certificates for Certificate Authorities, and any site I visit and use SSL/TLS should have a certificate signed by one of these trusted CAs for me to trust the site. My worry is that if someone has maliciously installed a certificate for these sites on my machine, they could perform a DNS spoofing attack (or a number of other attacks) to hijack my connection to my email account without me knowing, and as they've got the private counterpart to the certificate on my machine, decrypt the communication. NB: I'm also aware that CA certificates aren't just within Chromium and are used system wide as part of libssl - they're stored in /etc/ssl/certs. What I'd like to know is: Is this correct? - The big red boxes make me think no Is this malicious or benign? What can I do to resolve this problem? (If indeed it is a problem) Thanks :)

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  • Getting Server 2008 R2 to ignore all traffic from Internet-facing NIC, leaving it to a VM

    - by Wolvenmoon
    I got in to Server 2008 R2 via Dreamspark and would like to start learning on it. I don't have much option but to put it on a system sitting between the Internet and my home LAN due to electricity bills and the fact that 3 computers in an 11x11 space in 102 degree weather is pretty stygian. Currently I use a ClearOS gateway to manage everything, what I'd like to do is take my server 2008 R2 box, which has two NICs, and drop it at the head of my network. I'd want Server 2008 R2 to ignore all traffic on the external facing NIC and pass it to a virtual ClearOS gateway, and to put all its Internet traffic through its other NIC - which will face the rest of my network and be the default gateway for it. The theory is to keep the potentially vulnerable Server 2008 R2 install as tucked behind a Linux box as possible, without sacrificing too much performance. This is a home network that occasionally hosts dedicated game servers and voice chat servers, so most malicious activity is in the form of drive by non-targeted attacks, however, I don't trust Windows Server because I don't know the OS well enough, yet. So, three questions: How do I do this, am I going to be reasonably more secure doing this than if I just let the Server 2008 R2 rig handle all the network traffic and DHCP (not an option), and should I virtualize the Server 2008 R2 rig instead and if so in what? (Core 2 Duo e6600 w/ 5 gigs usable RAM)

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  • What's with the accesses to $random_existing_file/cache/df.php?

    - by Bernd Jendrissek
    Occasionally I eyeball Apache's access_log and lately I've been noticing these accesses to URLs that I don't serve. They're correctly 404'ed, but I'd like to know just who and what is involved here. "Obviously" it's some sort of vulnerability probing; I'd like to know which. (Not that it affects me, but I like to know the score.) Here's an example: 69.89.31.206 - - [28/Nov/2012:17:36:34 +0200] "GET /cvfull.pdf/cache/df.php HTTP/1.1" 404 489 "-" "-" Oddly, all 26 attempts are to either /cache/df.php, or to /cvfull.pdf/cache/df.php - they come in pairs. A few weeks ago it was zx.php, now it's df.php - I'm assuming the target is the same. Perhaps I should be flattered that a script is thinking of hiring me. Seriously, my CV is one of only two PDF files on my site, so I can only guess that non-PDF URLs aren't interesting? I've tried Googling for "cache df php", but my Google-fu is weak at the best of times, so I can only find a few reports of other script attacks. What's the vulnerability being scanned for here?

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  • What breaks in a Windows domain if a member has a high time skew?

    - by Ryan Ries
    It's taken for granted by most IT people that in a Windows domain, if a member server's clock is off by more than 5 minutes (or however many minutes you've configured it for) from that of its domain controller - logons and authentications will fail. But that is not necessarily true. At least not for all authentication processes on all versions of Windows. For instance, I can set my time on my Windows 7 client to be skewed all to heck - logoff/logon still works fine. What happens is that my client sends an AS_REQ (with his time stamp) to the domain controller, and the DC responds with KRB_AP_ERR_SKEW. But the magic is that when the DC responds with the aforementioned Kerberos error, the DC also includes his time stamp, which the client in turn uses to adjust his own time and resubmits the AS_REQ, which is then approved. This behavior is not considered a security threat because encryption and secrets are still being used in the communication. This is also not just a Microsoft thing. RFC 4430 describes this behavior. So my question is does anyone know when this changed? And why is it that other things fail? For instance, Office Communicator kicks me off if my clock starts drifting too far out. I really wish to have more detail on this. edit: Here's the bit from RFC 4430 that I'm talking about: If the server clock and the client clock are off by more than the policy-determined clock skew limit (usually 5 minutes), the server MUST return a KRB_AP_ERR_SKEW. The optional client's time in the KRB-ERROR SHOULD be filled out. If the server protects the error by adding the Cksum field and returning the correct client's time, the client SHOULD compute the difference (in seconds) between the two clocks based upon the client and server time contained in the KRB-ERROR message. The client SHOULD store this clock difference and use it to adjust its clock in subsequent messages. If the error is not protected, the client MUST NOT use the difference to adjust subsequent messages, because doing so would allow an attacker to construct authenticators that can be used to mount replay attacks.

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  • Disable IPv6 on Debian VPS (Virtuozzo!)

    - by chris_l
    I have a Debian Lenny VPS, that's running virtualized by Parallels/Virtuozzo. Currently, the network interface doesn't have an IPv6 address - and that's good, because I don't have an ip6tables configuration. But I assume, that I could wake up one day, and ifconfig will show me an ipv6 address for the interface - because I have no control over the kernel or its modules - they're under the control of the hosting company. That would leave the server completely vulnerable to attacks from IPv6 addresses. What would be the best way to disable IPv6 (for the interface or maybe for the entire host)? Usually I would simply disable the kernel module, but that's not possible in this case. Update Maybe I should add, that I can use iptables and everything normally (I'm root on the VPS), but I can't make changes to the kernel or load kernel modules because of the way Virtuozzo works (shared kernel). lsmod always returns nothing. I can't call ip6tables -L (it says that I need to insmod, or that the kernel would have to be upgraded). I don't think, that changes to /etc/modprobe.d/aliases would have any effect, or do they? Networking Config? I thought, that maybe I can turn IPv6 off from /etc/network/... Is that possible? I just see, that they've set up avahi, so I should probably change the setting use-ipv6=yes to "no" in /etc/avahi/avahi.conf (?) Has anybody already tried this solution, and can I rely on it? I don't know too much about avahi. Would it actually have any effect? Or could it even bring my entire interface down, once IPv6 is enabled by the kernel?

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  • CentOS security for lazy admins

    - by Robby75
    I'm running CentOS 5.5 (basic LAMP with Parallels Power Panel and Plesk) and have thus far neglected security (because it's not my full-time job, there is always something more important on my todo-list). My server does not contain any secret data and also no lives depend on it - Basically what I want is to make sure it does not become part of a botnet, that is "good enough" security in my case. Anyway, I don't want to become a full-time paranoid admin (like constantly watching and patching everything because of some obscure problem), I also don't care about most security problems like DOS attacks or problems that only exist when using some arcane settings. I'm in search of a "happy medium", for example a list of known important problems in the default installation of CentOS 5.5 and/or a list of security problems that have actually been exploited - not the typical endless list of buffer overflows that "maybe" a problem in some special case. The problem that I have with the usually recommended approaches (joining mailing lists, etc.) is that the really important problems (something where an exploit exists, that is exploitable in a common setup and where the attacker can do something really useful - i.e. not a DOS) are completely and utterly swamped by millions of tiny security alerts that surely are important for high-security servers, but not for me. Thanks for all suggestions!

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  • Running multiple sites on a LAMP with secure isolation

    - by David C.
    Hi everybody, I have been administering a few LAMP servers with 2-5 sites on each of them. These are basically owned by the same user/client so there are no security issues except from attacks through vulnerable deamons or scripts. I am builing my own server and would like to start hosting multiple sites. My first concern is... ISOLATION. How can I avoid that a c99 script could deface all the virtual hosts? Also, should I prevent that c99 to be able to write/read the other sites' directories? (It is easy to "cat" a config.php from another site and then get into the mysql database) My server is a VPS with 512M burstable to 1G. Among the free hosting managers, is there any small one which works for my VPS? (which maybe is compatible with the security approach I would like to have) Currently I am not planning to host over 10 sites but I would not accept that a client/hacker could navigate into unwanted directories or, worse, run malicious scripts. FTP management would be fine. I don't want to complicate things with SSH isolation. What is the best practice in this case? Basically, what do hosting companies do to sleep well? :) Thanks very much! David

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