High severity · published Aug 27, 2021
CVE-2021-40153
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
8.1
CVSS
2.5%
EPSS
No
On KEV
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
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.5% · higher than 85% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
EL
Enterprise Linux · Redhat
7.0; 8.0 · source: NVD
FE
Fedora · Fedoraproject
34; 33 · source: NVD
SQ
Squashfs-tools · Squashfs-tools Project
4.5 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-40153
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-40153
Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/squashfs-tools/+bug/1941790
Patch
https://github.com/plougher/squashfs-tools/commit/79b5a555058eef4e1e7ff220c344d39f8cd09646
Exploit
https://github.com/plougher/squashfs-tools/issues/72
Mailing List
https://lists.debian.org/debian-lts-announce/2021/08/msg00030.html
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GSMRKVJMJFX3MB7D3PXJSYY3TLZROE5S/
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RAOZ4BKWAC4Y3U2K5MMW3S77HWWXHQDL/
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