CVE-2021-31566

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Last Modified: UTC

ModerateModerate ImpactWhat does this mean?

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Description

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.

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.

Additional information

  • Bugzilla 2024237: libarchive: symbolic links incorrectly followed when changing modes, times, ACL and flags of a file while extracting an archive
  • CWE-59: Improper Link Resolution Before File Access ('Link Following')
  • FAQ: Frequently asked questions about CVE-2021-31566

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

7.1

7.8

Attack Vector

Local

Local

Attack Complexity

Low

Low

Privileges Required

None

None

User Interaction

Required

Required

Scope

Unchanged

Unchanged

Confidentiality Impact

None

High

Integrity Impact

High

High

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

My product is listed as "Out of Support Scope". What does this mean?

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