CVE-2020-5291
Published: 31 March 2020
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.
Notes
| Author | Note |
|---|---|
| seth-arnold | Bubblewrap isn't installed setuid by default on Ubuntu |
| mdeslaur | introduced in 0.4.0 |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
bubblewrap Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(code not present)
|
| eoan |
Not vulnerable
(code not present)
|
|
| focal |
Released
(0.4.0-1ubuntu4)
|
|
| groovy |
Released
(0.4.0-1ubuntu4)
|
|
| trusty |
Does not exist
|
|
| upstream |
Released
(0.4.1-1)
|
|
| xenial |
Does not exist
|
|
|
Patches: upstream: https://github.com/containers/bubblewrap/commit/1f7e2ad948c051054b683461885a0215f1806240 |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |