On December 8, 2020, Struts released a security bulletin disclosing a potential remote code execution vulnerability (CVE-2020-17530) in S2-061.
The vulnerability stems from insufficient input validation. This results in two forced Object Graph Navigation Library (OGNL) evaluations when the original user input is calculated.
When the OGNL expression is forced in Struts tag attributes and can be modified by external input, an attacker could craft a malicious OGNL expression to trigger the vulnerability.
The vulnerability has been fixed in Struts 2.5.26. Affected users are advised to upgrade to Struts 2.5.26 without delay.
For more information, see Struts’s security bulletin at the following link:
- Struts 2.0.0 – Struts 2.5.25
- Struts version >= Struts 2.5.26
Struts has officially released a new version to fix the preceding vulnerability. Users are advised to upgrade as soon as possible.
If users cannot upgrade for the time being, they should avoid using forced OGNL evaluation on untrusted user input to reduce risks.
The official security bulletin is available at the following link:
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