CVE-2025-71263

high

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

https://www.tuhs.org/pipermail/tuhs/2026-January/032991.html

https://www.spinellis.gr/blog/20251223/

https://sigma-star.at/blog/2025/12/unix-v4-buffer-overflow/

https://discuss.systems/@ricci/115747843169814700

http://www.openwall.com/lists/oss-security/2026/03/21/4

http://www.openwall.com/lists/oss-security/2026/03/20/6

Details

Source: Mitre, NVD

Published: 2026-03-13

Updated: 2026-03-21

Risk Information

CVSS v2

Base Score: 6.2

Vector: CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7.4

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00012