ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2021-31805

Apache Struts Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')

Published May 11, 2022 · catalog updated May 11, 2022 · Apache Struts

Patch now

CVE-2021-31805 is in the CISA known-exploited catalog. Confirm Apache Struts against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
85.43%
Remediation
Remediation guidance
Affected products
vendor Apache Struts

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. Initial-access exploit intelligence.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Apache Strutsversion unspecified

How to fix CVE-2021-31805

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-31805 is in the CISA known-exploited catalog. Confirm Apache Struts against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 85.43%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 11, 2022 · VulnCheck KEV

    Detected

    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. Initial-access exploit intelligence.

  2. May 11, 2022 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-31805

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-31805

    30-day exploitation probability 85.4%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-31805

    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 i

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.