#VU56306 Path traversal in squashfs-tools - CVE-2021-40153
Published: September 5, 2021 / Updated: March 18, 2022
Vulnerability identifier: #VU56306
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-40153
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
squashfs-tools
squashfs-tools
Software vendor:
plougher
plougher
Description
The vulnerability allows a remote user to compromise the affected system.
The vulnerability exists due to input validation error when processing directory traversal sequences within the squashfs_opendir in unsquash-1.c. A remote user can store the filename in the directory entry, which later is used by unsquashfs to create the new file during the unsquash. As a result, it is possible to write files to locations outside of the destination.
Remediation
Install update from vendor's website.
External links
- https://bugs.launchpad.net/ubuntu/+source/squashfs-tools/+bug/1941790
- https://github.com/plougher/squashfs-tools/commit/79b5a555058eef4e1e7ff220c344d39f8cd09646
- https://github.com/plougher/squashfs-tools/issues/72
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RAOZ4BKWAC4Y3U2K5MMW3S77HWWXHQDL/
- https://lists.debian.org/debian-lts-announce/2021/08/msg00030.html
- https://www.debian.org/security/2021/dsa-4967