| Name | CVE-2021-3995 |
| Description | A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more) |
| References | DSA-5055-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| util-linux (PTS) | buster | 2.33.1-0.1 | fixed |
| bullseye (security), bullseye | 2.36.1-8+deb11u1 | fixed | |
| bookworm, sid | 2.38.1-5 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| util-linux | source | stretch | (not affected) | |||
| util-linux | source | buster | (not affected) | |||
| util-linux | source | bullseye | 2.36.1-8+deb11u1 | DSA-5055-1 | ||
| util-linux | source | (unstable) | 2.37.3-1 |
[buster] - util-linux <not-affected> (Vulnerable code introduced later)
[stretch] - util-linux <not-affected> (Vulnerable code introduced later)
Introduced by: https://github.com/util-linux/util-linux/commit/5fea669e9ef0a08804f72bb40f859f239f68c30a (v2.34-rc1)
Fixed by: https://github.com/util-linux/util-linux/commit/f3db9bd609494099f0c1b95231c5dfe383346929 (v2.37.3)
https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes
https://www.openwall.com/lists/oss-security/2022/01/24/2