USN-5745-2: shadow regression
29 November 2022
USN-5745-1 introduced a regression in shadow.
Releases
Packages
- shadow - system login tools
Details
USN-5745-1 fixed vulnerabilities in shadow. Unfortunately that update
introduced a regression that caused useradd to behave incorrectly in Ubuntu
14.04 ESM, Ubuntu 16.04 ESM, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. This
update reverts the security fix pending further investigation.
We apologize for the inconvenience.
Original advisory details:
Florian Weimer discovered that shadow was not properly copying and removing
user directory trees, which could lead to a race condition. A local attacker
could possibly use this issue to setup a symlink attack and alter or remove
directories without authorization.
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04
-
passwd
-
1:4.8.1-1ubuntu5.20.04.4
-
login
-
1:4.8.1-1ubuntu5.20.04.4
-
uidmap
-
1:4.8.1-1ubuntu5.20.04.4
Ubuntu 18.04
Ubuntu 16.04
-
passwd
-
1:4.2-3.1ubuntu5.5+esm3
Available with Ubuntu Pro
-
login
-
1:4.2-3.1ubuntu5.5+esm3
Available with Ubuntu Pro
-
uidmap
-
1:4.2-3.1ubuntu5.5+esm3
Available with Ubuntu Pro
Ubuntu 14.04
-
passwd
-
1:4.1.5.1-1ubuntu9.5+esm3
Available with Ubuntu Pro
-
login
-
1:4.1.5.1-1ubuntu9.5+esm3
Available with Ubuntu Pro
-
uidmap
-
1:4.1.5.1-1ubuntu9.5+esm3
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.