CVE-2021-3995
Published: 1 February 2022
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.
Notes
| Author | Note |
|---|---|
| sbeattie |
introduced in 5fea669e9ef0a08804f72bb40f859f239f68c30a (v2.34) |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
util-linux
Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(code not present)
|
| focal |
Released
(2.34-0.1ubuntu9.3)
|
|
| impish |
Released
(2.36.1-8ubuntu2.2)
|
|
| jammy |
Released
(2.37.2-4ubuntu2)
|
|
| trusty |
Not vulnerable
(code not present)
|
|
| upstream |
Released
(2.37.3-1)
|
|
| xenial |
Not vulnerable
(code not present)
|
|
|
Patches:
upstream: https://github.com/util-linux/util-linux/commit/9c05f4b6bf62a20a64a8e5735c7f3dcf0229e895 upstream: https://github.com/util-linux/util-linux/commit/57202f5713afa2af20ffbb6ab5331481d0396f8d |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |