摘要: 来自TechNet的一篇文章，说实话，都流行了几年的东西了，现在突然当作宝贝一样这几天看到很多地方开始推这样的文章，包括HP、包括Symantec、包括Microsoft……早干什么去了？初中的小孩都会拿个工具扫描了、甚至可以手工写注入语句了……我还是在某些地...
来自TechNet的一篇文章，说实话，都流行了几年的东西了，现在突然当作宝贝一样
这几天看到很多地方开始推这样的文章，包括HP、包括Symantec、包括Microsoft……
早干什么去了？初中的小孩都会拿个工具扫描了、甚至可以手工写注入语句了……
我还是在某些地方加点标注吧，文章写的并不是那么完美……中文的是我添加的
by 网路游侠 https://www.youxia.org
(Special thanks to Neil Carpenter for helping out on this blog post)
Recent Trends
实际上，这个“最近的”趋势，已经有几年了，至少从2003年就开始在国内广泛流行，是的，是那时候开始“广泛流行”，而在国外，已经流行好久了……
Beginning late last year, a number of websites were defaced to include malicious HTML ＜script＞ tags in text that was stored in a SQL database and used to generate dynamic web pages. These attacks began to accelerate in the first quarter of 2008 and are continuing to affect vulnerable web applications.
The web applications compromised share several commonalities:
Application uses classic ASP code
不但有ASP注入，PHP和JSP的注入也相当流行，甚至有些EXE文件都可以注入……过分？是的，事实就是这样！
Application uses a SQL Server database
MySQL和Oracle、DB/2数据也是一样的，不但是SQL Server，只要功能不是太烂并且号称“数据库”貌似都行
Application code generates dynamic SQL queries based on URI query strings (http://consoto.com/widgets.asp?widget=sprocket)
This represents a new approach to SQL injection (http://msdn.microsoft.com/en-us/library/ms161953.aspx). In the past, SQL injection attacks were targeted to specific web applications where the vulnerabilities and the structure of the underlying database were either known or discovered by the attacker. This attack differs because it has been abstracted such that it is possible to attack virtually any vulnerability that is present in an ASP page creating dynamic SQL queries from URI query strings. Additional technical details and a walkthrough of the specifics are available at http://blogs.technet.com/neilcar/archive/2008/03/15/anatomy-of-a-sql-injection-incident-part-2-meat.aspx.
This attack does not exploit vulnerabilities in Windows, IIS, SQL Server, or other infrastructure code; rather, it exploits vulnerabilities in custom web applications running on this infrastructure. Microsoft has investigated these attacks thoroughly and determined that they are not related to any patched or 0-day vulnerabilities in Microsoft products. More information can be found at http://blogs.technet.com/msrc/archive/2008/04/25/questions-about-web-server-attacks.aspx.
As indicated above, these attacks have been accelerating through the year. This would appear to be related to at least two factors. First, there is a malicious tool that is in the wild that automates this. SANS discusses that tool here -- http://isc.sans.org/diary.html?storyid=4294. The tool uses search engines to find vulnerable sites to SQL injection.
The second factor is that one or more malicious bots are now launching SQL injection attacks as a way of spreading the bot further. SecureWorks discusses an example at http://www.secureworks.com/research/threats/danmecasprox/.
Once a server has been defaced using this attack, it will begin including a malicious ＜script＞ tag pointing to a .js file. While the contents of these files differ, they all attempt to exploit various vulnerabilities including already-patched Microsoft vulnerabilities and vulnerable third-party ActiveX controls. Since these scripts are hosted independently, it is possible that the scripts can be changed rapidly to exploit new client vulnerabilities and can be easily tailored to target on a “per browser” basis.
不仅仅是.js文件，SQL注入攻击是利用程序自身的问题，得到一定权限后写入文件，有时候是.js、有时候是＜iframe＞、有时候甚至是.css文件，都是可以成功利用刷流量或者进行进一步攻击、获取肉鸡的！
IT/database administrators Recommendations
There are a number of things that IT administrators and database administrators should do to limit risk and respond to possible incidents on the code and infrastructure they manage:
Review IIS logs and database tables for signs of previous exploits
Since this exploit takes place via the URI query string, administrators can review IIS logs to find anomalous queries that may be attempts to exploit this. Information on how to do this manually is available at http://blogs.technet.com/neilcar/archive/2008/03/15/anatomy-of-a-sql-injection-incident-part-2-meat.aspx. A sample of an automated tool is available at http://www.codeplex.com/Release/ProjectReleases.aspx?ProjectName=WSUS&ReleaseId=13436.
If IIS logs show that the server has possibly been exploited, the next step would be to inspect tables in databases that are used by the associated web applications, looking for ＜script＞ tags appended to cells in text columns.
NOTE: IIS servers should never run in production with logging disabled. While the storage and administration requirements of IIS logging can be significant, the lack of IIS logs makes it very difficult to respond to security incidents.
If running 3rd party code that uses a database back-end, consult ISV about susceptibility to SQL injection
In cases where 3rd party ASP web applications are being used, administrators should contact the application vendors to ensure that they are not susceptible to SQL injection attacks.
第三方的防止SQL注入攻击的产品很多，包括现在很多防火墙、IPS、专用的防注入防火墙都可以起到比较好的作用，另外也有防注入的脚本，过滤一些直接提交的SQL语句，比如：or、and、select、drop、insert等，就可以很有效的起到过滤作用，一般可以直接在conn.asp等数据库连接文件中调用，效果很明显。同样的，作者还是在说ASP应用，实际上几乎所有的语言都有这个问题！因为这个是数据库的特性！PHP、JSP都无一例外，甚至C、Pascal、Perl、Python等写的程序依然可以注入，因为这个是程序自身的问题，只要你愿意，你甚至可以用汇编写SQL注入的例子。以前有杂志曾经将结果EXE的注入，后来我自己也尝试过，成功构造语句进入了一个需要密码才能进入的EXE程序
Validate that the account(s) that are used from the web application have least possible privilege in the database
Administrators should make sure that the SQL users that the web application uses have the least privilege necessary. Web applications should never connect as users with administrative privilege such as “sysadmin” at the server level or “db_owner” at the database level. The white paper “best practices for setting up and maintaining security in SQL Server 2005” http://download.microsoft.com/download/8/5/e/85eea4fa-b3bb-4426-97d0-7f7151b2011c/SQL2005SecBestPract.doc provides recommendations for various aspects of SQL server security.
Web developers Recommendations
There are several good documents on how Web developers can prevent SQL injection attacks when writing code. Since these attacks leverage vulnerable web application code, the only way to completely prevent them is to resolve vulnerabilities in the code. Any place that the code dynamically generates a SQL query using data from an external source (and, particularly, from a URI query string) should be considered suspect. Once code vulnerabilities are identified, they need to be carefully resolved.
Explained – SQL Injection, ASP.NET, ADO.NET:
http://msdn.microsoft.com/en-us/library/bb671351.aspx
Also, the above document contains a pointer to the following article “How T
o: Protect From SQL Injection in ASP.NET” http://msdn.microsoft.com/en-us/library/ms998271.aspx (which still applies to ASP)
A very useful video can be found here (this is the video refer on the previous article, but that link is currently broken): http://channel9.msdn.com/wiki/default.aspx/SecurityWiki.SQLInjectionLab
Generic information about how SQL Injection works:
http://msdn.microsoft.com/en-us/library/ms161953.aspx
SQL injections in ASP code (this is different from ASP.NET!):
http://msdn.microsoft.com/en-us/library/cc676512.aspx
How to call SQL Server stored procedures from ASP:
http://support.microsoft.com/kb/q164485
The Microsoft Security Development Lifecycle (SDL) has specific guidance to defend against SQL injection. In simple terms there are three different strategies to eradicate SQL Injection attacks:
Using SQL parameterized queries
Using stored procedures
Using SQL execute-only permissions
Michael Howard covers those topics in http://blogs.msdn.com/sdl/archive/2008/05/15/giving-sql-injection-the-respect-it-deserves.aspx
Also, Writing Secure Code 2nd has good guidance on how to prevent these type of attacks as well (see pages 399-411)
SQL Injection Mitigation: Using Parameterized Queries (Part 1 & 2). The advantage of using parameterized queries is that it separates the executable code (ie, the SELECT statement) from the data (the dynamic information supplied by the application’s user). This approach prevents any malicious statements passed along by the user from executing.
Part 1: http://blogs.technet.com/neilcar/archive/2008/05/21/sql-injection-mitigation-using-parameterized-queries.aspx
Part 2: http://blogs.technet.com/neilcar/archive/2008/05/23/sql-injection-mitigation-using-parameterized-queries-part-2-types-and-recordsets.aspx
Filtering SQL injection form Classic ASP code (or blacklisting keywords), we considered the below as temporary workarounds since in reality it does not fix the root cause of the bugs (i.e. the code is still vulnerable and it might be reachable even after the filtering)
Nazim from the IIS team explains how to do the filtering in detail here: http://blogs.iis.net/nazim/archive/2008/04/28/filtering-sql-injection-from-classic-asp.aspx
If you are still not sure where to start, all web code that accesses a database with a particular focus on ASP code and areas of code which use user-supplied data should be review first.
End User Recommendations
End users should review the information at http://www.microsoft.com/protect/default.mspx; in addition, here are some specific steps that you can take to protect yourself.
As always, browse responsibly — but be aware that this could also affect websites that the user trusts
While responsible browsing limits your exposure to vulnerability, it is possible that even websites you trust may have been compromised. Watch for unusual behavior, be aware of the risk, and implement the other recommendations in this section.
Keep up to date on security updates, both Microsoft and 3rd party
Since the malicious scripts are exploiting known vulnerabilities, you should make sure that you are running the latest Microsoft and 3rd party security updates. Microsoft security updates are available via http://update.microsoft.com. Additional information is available at http://www.microsoft.com/protect/computer/updates/OS.aspx.
Disable unneeded ActiveX controls and Internet Explorer add-ons
You should disable any unneeded ActiveX controls and add-ons in Internet Explorer. To do this on Windows XP Service Pack 2 or later, follow these steps from KB883256 (http://support.microsoft.com/kb/883256):
1. Start Internet Explorer.
2. On the Tools menu, click Manage Add-ons.
3. Click the name of the add-on.
4. Use one of the following methods:
• Click Update ActiveX to replace the add-on with the current version. This option is not available for all add-ons.
• To enable an add-on, click Enable, and then click OK.
• To disable an add-on, click Disable, and then click OK.
You may have to restart Internet Explorer for the changes to take effect after you enable or disable an add-on.
For earlier operating systems, follow the instructions in KB154036 (http://support.microsoft.com/kb/154036).
Take steps to reduce attack surface of 3rd party browsers if you are using them
If you are using an Internet browser other than Internet Explorer, you should ensure that you have installed the latest security updates and that you disable unneeded extensions and add-ons. Information for popular browsers can be found at:
Firefox - http://support.mozilla.com/en-US/kb/Firefox+Support+Home+Page
Opera - http://www.opera.com/support/
Safari - http://www.apple.com/support/safari/
Run up-to-date anti-malware software
End users should ensure that they have anti-virus and anti-spyware software installed and that it is up to date. More information can be found at http://www.microsoft.com/protect/computer/antivirus/OS.aspx and http://www.microsoft.com/protect/computer/antispyware/OS.aspx. You can get a 90-day trial copy of Windows Live OneCare anti-virus/anti-spyware software at http://onecare.live.com/standard/en-us/install/install.htm.
- Security Vulnerability Research & Defense Bloggers
*Postings are provided "AS IS" with no warranties, and confers no rights.*
Published Thursday, May 29, 2008 10:20 PM by swiblog
Filed under: Injection, SQL, Attack
http://blogs.technet.com/swi/archive/2008/05/29/sql-injection-attack.aspx
后面的很多不想添加了，前面说的差不多了
注入是程序员在写程序的时候过滤不严格导致的安全问题
和语言无关、和数据库类型无关
最好的防范手段是找个安全意识好的程序员
写程序的时候不要片面追求功能，因为功能永远和安全成反比
如果可能，购买相关软件或硬件产品进行防范
当然，安全配置也相当的重要
万一被攻克了，至少能防止权限被进一步提升
如果你想检测自己的网站是不是也有这样的问题
可以尝试下列几个工具：
NBSI、啊D注入工具、明小子的Domain、CASI 注射器、HDSI
新版本的X-Scan也行
商业的有WebRavor、SSS、榕基RJ-iTop、绿盟极光、Venus天镜
西安用户需要此类产品可以和我——网路游侠联系。QQ：55984512，电子邮件：zbc98@163.com
