Bubblewrap

bubblewrap is a low-level unprivileged sandboxing tool. From version 0.11.0 to before version 0.11.2, if bubblewrap is installed in setuid mode then the user can use ptrace to attach to bubblewrap and control the unprivileged part of the sandbox setup phase. This allows the attacker to arbitrarily use the privileged operations, and in particular the "overlay mount" operation, allowing the creation of overlay mounts which is otherwise not allowed in the setuid version of bubblewrap. This issue has been patched in version 0.11.2.

Published: 2026-05-09T03:56:51.833Z
Updated: 2026-08-24T12:07:07.444Z

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.

Published: 2020-03-31T18:00:18.000Z
Updated: 2024-08-04T08:22:09.099Z