| Name | CVE-2016-2779 |
| Description | runuser in util-linux allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes characters to the terminal's input buffer. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 815922 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| util-linux (PTS) | jessie, jessie (lts) | 2.26.2+really2.25.2-6+deb8u2 | vulnerable |
| stretch (security) | 2.29.2-1+deb9u1 | vulnerable |
| stretch (lts), stretch | 2.29.2-1+deb9u3 | vulnerable |
| buster (security), buster, buster (lts) | 2.33.1-0.1+deb10u1 | fixed |
| bullseye (security), bullseye | 2.36.1-8+deb11u2 | fixed |
| bookworm | 2.38.1-5+deb12u2 | fixed |
| bookworm (security) | 2.38.1-5+deb12u1 | fixed |
| sid, trixie | 2.40.2-12 | fixed |
The information below is based on the following data on fixed versions.
Notes
[stretch] - util-linux <no-dsa> (Minor issue)
[jessie] - util-linux <no-dsa> (Minor issue)
[wheezy] - util-linux <not-affected> (runuser[.c] not yet present)
[squeeze] - util-linux <not-affected> (runuser[.c] not yet present)
Restricting ioctl on the kernel side seems the better approach, patches have been posted to kernel-hardening list
https://www.openwall.com/lists/oss-security/2016/02/27/1
https://marc.info/?l=util-linux-ng&m=145694736107128&w=2
2.31 introduces a new --pty option to separate privileged and unprivileged
shells (not enabled by default and the cli switch is necessary).