CVE Vulnerabilities

CVE-2020-27833

Improper Link Resolution Before File Access ('Link Following')

Published: May 14, 2021 | Modified: Feb 21, 2024
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
4.6 MEDIUM
AV:N/AC:H/Au:S/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

A Zip Slip vulnerability was found in the oc binary in openshift-clients where an arbitrary file write is achieved by using a specially crafted raw container image (.tar file) which contains symbolic links. The vulnerability is limited to the command oc image extract. If a symbolic link is first created pointing within the tarball, this allows further symbolic links to bypass the existing path check. This flaw allows the tarball to create links outside the tarballs parent directory, allowing for executables or configuration files to be overwritten, resulting in arbitrary code execution. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. Versions up to and including openshift-clients-4.7.0-202104250659.p0.git.95881af are affected.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Openshift_container_platform Redhat * 4.7 (including)

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References