CVE-2021-31805: Forced OGNL evaluation, when evaluated on raw not validated user input in tag attributes, may lead to RCE.
The fix issued for CVE-2020-17530 was incomplete. So from Apache Struts 2.0.0 to 2.5.29, still some of the tag’s attributes could perform a double evaluation if a developer applied forced OGNL evaluation by using the %{...} syntax. Using forced OGNL evaluation on untrusted user input can lead to a Remote Code Execution and security degradation.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2021-31805?
CVE-2021-31805 is a vulnerability in Apache Struts 2.0.0 to 2.5.29 that allows for double evaluation of tag attributes when forced OGNL evaluation is used.
How severe is CVE-2021-31805?
CVE-2021-31805 is classified as a critical vulnerability with a severity score of 9.8.
How does CVE-2021-31805 affect Apache Struts?
CVE-2021-31805 affects Apache Struts versions 2.0.0 to 2.5.29, allowing for potential double evaluation of tag attributes.
What is forced OGNL evaluation?
Forced Object-Graph Navigation Language (OGNL) evaluation is a feature that allows developers to evaluate expressions within tags or templates.
How can I fix CVE-2021-31805?
To fix CVE-2021-31805, users are advised to upgrade Apache Struts to a version beyond 2.5.29.