CVE-2019-18276

Priority
Description
An issue was discovered in disable_priv_mode in shell.c in GNU Bash through
5.0 patch 11. By default, if Bash is run with its effective UID not equal
to its real UID, it will drop privileges by setting its effective UID to
its real UID. However, it does so incorrectly. On Linux and other systems
that support "saved UID" functionality, the saved UID is not dropped. An
attacker with command execution in the shell can use "enable -f" for
runtime loading of a new builtin, which can be a shared object that calls
setuid() and therefore regains privileges. However, binaries running with
an effective UID of 0 are unaffected.
Notes
Package
Source: bash (LP Ubuntu Debian)
Upstream:needs-triage
Ubuntu 12.04 ESM (Precise Pangolin):needs-triage
Ubuntu 14.04 ESM (Trusty Tahr):needs-triage
Ubuntu 16.04 LTS (Xenial Xerus):needs-triage
Ubuntu 18.04 LTS (Bionic Beaver):needs-triage
Ubuntu 19.04 (Disco Dingo):needs-triage
Ubuntu 19.10 (Eoan Ermine):needs-triage
Ubuntu 20.04 (Focal Fossa):needs-triage
Patches:
Upstream:https://git.savannah.gnu.org/cgit/bash.git/commit/?h=devel&id=951bdaad7a18cc0dc1036bba86b18b90874d39ff
More Information

Updated: 2019-12-05 20:04:57 UTC (commit 0aa5e7c87c8b55d2ec5c7f4ca1179cf75de91961)