CVE-2021-41072

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-09-14 · updated 2026-06-17
Weakness: CWE-22

Description

squashfs_opendir in unsquash-2.c in Squashfs-Tools 4.5 allows Directory Traversal, a different vulnerability than CVE-2021-40153. A squashfs filesystem that has been crafted to include a symbolic link and then contents under the same filename in a filesystem can cause unsquashfs to first create the symbolic link pointing outside the expected directory, and then the subsequent write operation will cause the unsquashfs process to write through the symbolic link elsewhere in the filesystem.

Affected products

Debian Linux: 9.0, 10.0, 11.0
Squashfs-Tools Project Squashfs-Tools: 4.5

References

https://github.com/plougher/squashfs-tools/commit/e0485802ec72996c20026da320650d8362f555bd
https://github.com/plougher/squashfs-tools/issues/72#issuecomment-913833405
https://lists.debian.org/debian-lts-announce/2021/10/msg00017.html
https://security.gentoo.org/glsa/202305-29
https://www.debian.org/security/2021/dsa-4987
https://github.com/plougher/squashfs-tools/commit/e0485802ec72996c20026da320650d8362f555bd
https://github.com/plougher/squashfs-tools/issues/72#issuecomment-913833405
https://lists.debian.org/debian-lts-announce/2021/10/msg00017.html
https://security.gentoo.org/glsa/202305-29
https://www.debian.org/security/2021/dsa-4987

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