Richard Weinberger reported that unsquashfs in squashfs-tools, the tools
to create and extract Squashfs filesystems, does not check for duplicate
filenames within a directory. An attacker can take advantage of this
flaw for writing to arbitrary files to the filesystem if a malformed
Squashfs image is processed.
For the oldstable distribution (buster), this problem has been fixed
in version 1:4.3-12+deb10u2.
For the stable distribution (bullseye), this problem has been fixed in
We recommend that you upgrade your squashfs-tools packages.
For the detailed security status of squashfs-tools please refer to its
security tracker page at:
Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/
Mailing list: [email protected]
Debian Security Advisory DSA-4987-1 [email protected]
https://www.debian.org/security/ Salvatore Bonaccorso
October 15, 2021 https://www.debian.org/security/faq