VulnerabilityModified

CVE-2020-5291

HIGH 7.8EPSS 0.91%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.91%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.91% probability · 58th percentile
CISA KEV: Not listed
Weakness: CWE-648, CWE-269
Affected: projectatomic/bubblewrap · debian/debian linux · archlinux/arch linux · centos/centos
Source: security-advisories@github.com

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.