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Vulnerabilities

Vulnerability · CVE-2021-20231

A flaw was found in gnutls.

Published Mar 12, 2021 · catalog updated Oct 14, 2026 · A flaw was found

Check if you run it

No confirmed exploitation is on record for CVE-2021-20231. EPSS is 3.80%. Act only if a listed version of A flaw was found is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A flaw was found).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
3.80%
Remediation
Not established
Affected products
cpe fedoraproject/fedora · cpe gnu/gnutls · cpe netapp/active iq unified manager · cpe netapp/e-series performance analyzer · cpe redhat/enterprise linux

A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.

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.

  • cpe fedoraproject/fedora34
  • cpe gnu/gnutlsversion unspecified
  • cpe netapp/active iq unified managerversion unspecified
  • cpe netapp/e-series performance analyzerversion unspecified
  • cpe redhat/enterprise linux8.0

How to fix CVE-2021-20231

What to do

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

Should you patch?

No confirmed exploitation is on record for CVE-2021-20231. EPSS is 3.80%. Act only if a listed version of A flaw was found is installed.

Which versions are affected?

Compare what you have installed with redhat/enterprise linux 8.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 3.80%. There is no CISA KEV listing. 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. Mar 12, 2021 · NIST NVD

    Detected

    A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.

  2. Oct 14, 2026 · NIST NVD

    Updated

    A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.

Sources

  • CVE.orgVulnerability recordCVE-2021-20231

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-20231

    30-day exploitation probability 3.8%

    first.org
  • NIST NVDVulnerability recordCVE-2021-20231

    A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.