Summary
Excerpt |
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Double Forced double OGNL evaluation, when using evaluated on raw user input in tag 's attributesattributes, may lead to remote code execution. |
Who should read this | All Struts 2 developers and users |
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Impact of vulnerability | Possible Remote Code Execution vulnerability |
Maximum security rating | Important |
Recommendation | Always validate incoming parameters' values when re-assigning them to certain Struts' tags attributes. Don't use %{...} syntax in tag attributes other than value unless you have a valid use-case. Alternatively upgrade to Struts 2.3.20.3, Struts 2.3.2624.3 or Struts 2.3.28 |
Affected Software | Struts 2.0.0 - Struts Struts 2.3.24.1 (except 2.3.20.3) |
ReportersReporter | Romain Gaucher rgaucher at coverity dot com - Coverity Lupin lupin1314 at gmail dot com - jd.com security team nike.zheng at dbappsecurity dot com dot cn - dbappsecurity team genxors at gmail dot com - Qihoo 360 SkyEye Lab |
CVE Identifier | CVE-2016-0785 |
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The Apache Struts frameworks when forced, performs double evaluation of attributes' values assigned to certain tags so it is possible to pass in a value that will be evaluated again when a tag's attributes will be rendered.
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Adding a proper validation of each value that's coming in and it's used in tag's attributes. Alternatively .
Don't use forced evaluation of an attribute other than value using %{...} syntax unless really needed for a valid use-case.
By upgrading to Struts 2.3.20.3, 2.3.24.3 and 2.3.28, possible malicious effects of forced double evaluation are limitedupgrade to Struts 2.3.26.
Backward compatibility
No issues expected when upgrading to Struts 2.3.20.3, 2.3.26
Workaround
24.3 and 2.3.28
Workaround
If you are using Struts 2.3.20, 2.3.24 or 2.3.24.1 you can redefine struts.excludedClasses
as showed below, for more details please read internal security page.
Code Block | ||||
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<constant name="struts.excludedClasses"
value="
java.lang.Object,
java.lang.Runtime,
java.lang.System,
java.lang.Class,
java.lang.ClassLoader,
java.lang.Shutdown,
java.lang.ProcessBuilder,
ognl.OgnlContext,
ognl.ClassResolver,
ognl.TypeConverter,
com.opensymphony.xwork2.ognl.SecurityMemberAccess,
com.opensymphony.xwork2.ActionContext" /> |
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