CVE-2021-40153 Information

Description

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory and thus allows writing to locations outside of the destination.

CVSS Vector

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

Reference

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 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GSMRKVJMJFX3MB7D3PXJSYY3TLZROE5S/

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.1