Samba up to 4.21.5 Group Membership Change improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Samba up to 4.21.5. It has been rated as critical. This impacts an unknown function of the component Group Membership Change Handler. The manipulation leads to improper authentication. This vulnerability is referenced as CVE-2025-0620. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Samba up to 4.21.5 and classified as problematic. This issue affects an unknown function of the component Group Membership Change Handler. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

The advisory is shared at seclists.org. The identification of this vulnerability is CVE-2025-0620 since 01/21/2025. The exploitation is known to be difficult. The attack may be initiated remotely. The exploitation requires an enhanced level of successful authentication. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 237874 (Fedora 43 : samba (2025-a0d44a3ecf)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.21.6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (237874). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.1
VulDB Temp Score: 3.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.9
NVD Vector: 🔍

CNA Base Score: 4.9
CNA Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 237874
Nessus Name: Fedora 43 : samba (2025-a0d44a3ecf)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Samba 4.21.6

Timelineinfo

01/21/2025 🔍
06/03/2025 +132 days 🔍
06/03/2025 +0 days 🔍
01/08/2026 +219 days 🔍

Sourcesinfo

Product: samba.org

Advisory: seclists.org
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2025-0620 (🔍)
GCVE (CVE): GCVE-0-2025-0620
GCVE (VulDB): GCVE-100-311045

Entryinfo

Created: 06/03/2025 22:54
Updated: 01/08/2026 05:38
Changes: 06/03/2025 22:54 (54), 06/06/2025 16:07 (2), 06/09/2025 14:27 (13), 11/18/2025 17:55 (11), 01/08/2026 05:38 (6)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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