AT&T Bell Labs UNIX 4 Password buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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5.9$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in AT&T Bell Labs UNIX 4. Affected by this vulnerability is an unknown functionality. Executing a manipulation of the argument Password can lead to buffer overflow. This vulnerability is registered as CVE-2025-71263. The attack needs to be launched locally. No exploit is available.

Detailsinfo

A vulnerability classified as critical was found in AT&T Bell Labs UNIX 4. This vulnerability affects some unknown functionality. The manipulation of the argument password with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at sigma-star.at. This vulnerability was named CVE-2025-71263 since 03/13/2026. The exploitation appears to be difficult. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-208655). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.9

VulDB Base Score: 4.5
VulDB Temp Score: 4.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.4
CNA Vector (MITRE): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/13/2026 Advisory disclosed
03/13/2026 +0 days CVE reserved
03/13/2026 +0 days VulDB entry created
03/22/2026 +8 days VulDB entry last update

Sourcesinfo

Advisory: sigma-star.at
Status: Confirmed

CVE: CVE-2025-71263 (🔒)
GCVE (CVE): GCVE-0-2025-71263
GCVE (VulDB): GCVE-100-351010
EUVD: 🔒

Entryinfo

Created: 03/13/2026 20:21
Updated: 03/22/2026 00:16
Changes: 03/13/2026 20:21 (63), 03/13/2026 21:49 (1), 03/20/2026 03:07 (1), 03/22/2026 00:16 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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