UBUNTU-CVE-2021-3995

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Source
https://ubuntu.com/security/CVE-2021-3995
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3995.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-3995
Upstream
Downstream
Related
Published
2022-02-01T00:00:00Z
Modified
2025-07-16T07:43:13.463864Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:20.04:LTS / util-linux

Package

Name
util-linux
Purl
pkg:deb/ubuntu/util-linux@2.34-0.1ubuntu9.3?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.34-0.1ubuntu9.3

Affected versions

2.*

2.34-0.1ubuntu2
2.34-0.1ubuntu4
2.34-0.1ubuntu5
2.34-0.1ubuntu6
2.34-0.1ubuntu7
2.34-0.1ubuntu8
2.34-0.1ubuntu9
2.34-0.1ubuntu9.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bsdutils",
            "binary_version": "1:2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "bsdutils-dbgsym",
            "binary_version": "1:2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "fdisk",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "fdisk-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "fdisk-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libblkid-dev",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libblkid1",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libblkid1-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libblkid1-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libfdisk-dev",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libfdisk1",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libfdisk1-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libfdisk1-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libmount-dev",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libmount1",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libmount1-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libmount1-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libsmartcols-dev",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libsmartcols1",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libsmartcols1-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libsmartcols1-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libuuid1",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libuuid1-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "libuuid1-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "mount",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "mount-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "rfkill",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "rfkill-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "util-linux",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "util-linux-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "util-linux-locales",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "util-linux-udeb",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "uuid-dev",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "uuid-runtime",
            "binary_version": "2.34-0.1ubuntu9.3"
        },
        {
            "binary_name": "uuid-runtime-dbgsym",
            "binary_version": "2.34-0.1ubuntu9.3"
        }
    ],
    "availability": "No subscription required"
}

Ubuntu:22.04:LTS / util-linux

Package

Name
util-linux
Purl
pkg:deb/ubuntu/util-linux@2.37.2-4ubuntu2?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.37.2-4ubuntu2

Affected versions

2.*

2.36.1-8ubuntu1
2.37.2-4ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bsdextrautils",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "bsdextrautils-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "bsdutils",
            "binary_version": "1:2.37.2-4ubuntu2"
        },
        {
            "binary_name": "bsdutils-dbgsym",
            "binary_version": "1:2.37.2-4ubuntu2"
        },
        {
            "binary_name": "eject",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "eject-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "fdisk",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "fdisk-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libblkid-dev",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libblkid1",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libblkid1-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libfdisk-dev",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libfdisk1",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libfdisk1-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libmount-dev",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libmount1",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libmount1-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libsmartcols-dev",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libsmartcols1",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libsmartcols1-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libuuid1",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "libuuid1-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "mount",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "mount-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "rfkill",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "rfkill-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "util-linux",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "util-linux-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "util-linux-locales",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "uuid-dev",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "uuid-runtime",
            "binary_version": "2.37.2-4ubuntu2"
        },
        {
            "binary_name": "uuid-runtime-dbgsym",
            "binary_version": "2.37.2-4ubuntu2"
        }
    ],
    "availability": "No subscription required"
}