CVE-2021-20251

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-03-06 · updated 2026-06-17
Weakness: CWE-362

Description

A flaw was found in samba. A race condition in the password lockout code may lead to the risk of brute force attacks being successful if special conditions are met.

Affected products

Fedoraproject Fedora: 37
Samba: from 4.1.0 before 4.16.8; from 4.17.0 before 4.17.4 — fixed in 4.16.8, 4.17.4

How to fix

Upgrade to a fixed version: Samba 4.16.8, 4.17.4. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1929800
https://bugzilla.samba.org/show_bug.cgi?id=14611
https://security.gentoo.org/glsa/202309-06
https://security.netapp.com/advisory/ntap-20230331-0005/
https://bugzilla.redhat.com/show_bug.cgi?id=1929800
https://bugzilla.samba.org/show_bug.cgi?id=14611
https://security.gentoo.org/glsa/202309-06
https://security.netapp.com/advisory/ntap-20230331-0005/

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