CVE-2020-5291
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 57% of all known CVEs.
References
Related Vulnerabilities
Other CWE-648 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2026-20122 | Medium | 5.4 | 25% | KEV | Fix |
| CVE-2019-14813 | Critical | 9.8 | 11% | - | Fix |
| CVE-2024-8785 | Critical | 9.8 | 9.7% | - | Fix |
| CVE-2025-54766 | Medium | 5.3 | 7.2% | - | - |
| CVE-2025-54765 | Medium | 5.3 | 7.2% | - | - |
| CVE-2025-54767 | Medium | 6.5 | 5.7% | - | - |
Common questions
How do I fix CVE-2020-5291?
Upgrade bubblewrap on debian 11 to 0.4.1-1 or later.
Is CVE-2020-5291 being actively exploited?
Not that we know of. CVE-2020-5291 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.91% is the estimated probability that it will be exploited in the next 30 days. That is higher than 57% of all scored CVEs.
How severe is CVE-2020-5291?
CVE-2020-5291 has a CVSS v3 base score of 7.2, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2020-5291 affect?
Published advisories record a fix for bubblewrap (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.