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CVE

CWE

Training

CVE-2025-71263

Published: Mar 13, 2026

Modified: Mar 21, 2026

PUBLISHED

CVSS v3.1

7.4

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.

Vendor	Product	Versions
AT&T Bell Labs	UNIX	affected `4`

Weaknesses (CWE)

CVSS v3.1 Details

CVSS v3.1 Vector

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

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

References

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

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

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

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

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