ZDF
Sign inSign up

Vulnerabilities

Security incident · CVE-2021-31566

An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive.

Published Aug 23, 2022 · catalog updated Nov 2, 2026 · An improper link resolution

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2021-31566. EPSS is 0.39%. Act only if a listed version of An improper link resolution is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (An improper link resolution).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.39%
Remediation
Version ranges on file
Affected products
cpe libarchive/libarchive · cpe redhat/enterprise linux · cpe redhat/enterprise linux eus · cpe redhat/enterprise linux for ibm z systems · cpe redhat/enterprise linux for ibm z systems eus · cpe redhat/enterprise linux for power little endian

An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to gain more privileges in a system.

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 libarchive/libarchive< 3.5.2
  • cpe redhat/enterprise linux8.0
  • cpe redhat/enterprise linux eus8.6
  • cpe redhat/enterprise linux for ibm z systems8.0
  • cpe redhat/enterprise linux for ibm z systems eus8.6
  • cpe redhat/enterprise linux for power little endian8.0
  • cpe redhat/enterprise linux for power little endian eus8.6
  • cpe redhat/enterprise linux server aus8.6

How to fix CVE-2021-31566

  • Upgrade

    CVE-2021-31566 lists a fix boundary at 3.5.2. Compare the installed build with that boundary before you change production.

  • Version check

    Affected < 3.5.2

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

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-2021-31566. EPSS is 0.39%. Act only if a listed version of An improper link resolution is installed.

Which versions are affected?

Compare what you have installed with redhat/enterprise linux 8.0; redhat/enterprise linux eus 8.6; redhat/enterprise linux for ibm z systems 8.0; redhat/enterprise linux for ibm z systems eus 8.6. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-59: Link Following. EPSS 0.39%. 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.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 23, 2022 · NIST NVD

    Detected

    An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to gain more privileges in a system.

  2. Nov 2, 2026 · NIST NVD

    Updated

    An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to gain more privileges in a system.

Sources

  • CVE.orgVulnerability recordCVE-2021-31566

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2021-31566

    An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extr

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 4, 2026
  • NIST NVDNov 2, 2026