CVE-2020-5291 - CVE House
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Status published High CVE-2020-5291

Privilege escalation in setuid mode via user namespaces in Bubblewrap

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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High 8.5

Affected Vendor

Affected Software

bubblewrap
Vulnerable Versions:
< 0.4.1

Timeline

Official Publish: March 31st, 2020
Last Modified: August 4th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

Weaknesses (CWE)

CWE-648

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.