CVE-2020-5291

Name: CVE-2020-5291
Creator: NVD / NIST
Published: 2020-03-31T18:15:26.963+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.91%

Last modified Jun 17, 2026

CVE-2020-5291 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. EPSS estimates a 0.91% chance of exploitation in the next 30 days.

Description

Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the `bwrap --userns2` option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. Note that this only affects the combination of bubblewrap in setuid mode (which is typically used when unprivileged user namespaces are not supported) and the support of unprivileged user namespaces. Known to be affected are: * Debian testing/unstable, if unprivileged user namespaces enabled (not default) * Debian buster-backports, if unprivileged user namespaces enabled (not default) * Arch if using `linux-hardened`, if unprivileged user namespaces enabled (not default) * Centos 7 flatpak COPR, if unprivileged user namespaces enabled (not default) This has been fixed in the 0.4.1 release, and all affected users should update.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.91%

55.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Projectatomic	Bubblewrap	< 0.4.1
Debian	Debian Linux	10.0
Archlinux	Arch Linux	All versions
Centos	Centos	7.0

References

https://github.com/containers/bubblewrap/commit/1f7e2ad948c051054b683461885a0215f1806240Patch, Third Party Advisory
https://github.com/containers/bubblewrap/security/advisories/GHSA-j2qp-rvxj-43vjMitigation, Third Party Advisory
https://github.com/containers/bubblewrap/commit/1f7e2ad948c051054b683461885a0215f1806240Patch, Third Party Advisory
https://github.com/containers/bubblewrap/security/advisories/GHSA-j2qp-rvxj-43vjMitigation, Third Party Advisory

Timeline

Published: Mar 31, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-5291?

How severe is CVE-2020-5291?

CVE-2020-5291 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.91% probability of exploitation in the next 30 days.

How do I fix CVE-2020-5291?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-5291?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST