Description
The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty. This allows local users to login as password-less users even if they are connected by non-physical means such as SSH (hence bypassing PAM's nullok_secure configuration). This notably affects environments such as virtual machines automatically generated with a default blank root password, allowing all local users to escalate privileges.
References (3)
Core 3
Core References
Mailing List, Vendor Advisory x_refsource_misc
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=877374
Exploit, Mailing List, Vendor Advisory x_refsource_misc
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914957
Mailing List, Vendor Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/03/msg00020.html
Scores
CVSS v3
7.8
EPSS
0.0040
EPSS Percentile
32.3%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-269
Status
published
Products (2)
debian/debian_linux
9.0
debian/shadow
4.4
Published
Mar 17, 2021
Tracked Since
Feb 18, 2026