Description
In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
References (6)
Core 6
Core References
Various Sources
https://discuss.systems/@ricci/115747843169814700
Various Sources
https://sigma-star.at/blog/2025/12/unix-v4-buffer-overflow/
Various Sources
https://www.spinellis.gr/blog/20251223/
Various Sources
https://www.tuhs.org/pipermail/tuhs/2026-January/032991.html
Scores
CVSS v3
7.4
EPSS
0.0018
EPSS Percentile
7.6%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-120
Status
published
Products (2)
AT&T Bell Labs/UNIX
4
opengroup/unix
4
Published
Mar 13, 2026
Tracked Since
Mar 14, 2026