Denial of service in Samba

Published: 2021-10-13
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-3671
Exploitation vector Local network
Public exploit N/A
Vulnerable software
Server applications / Directory software, identity management

Vendor Samba

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) NULL pointer dereference

EUVDB-ID: #VU57324

Risk: Medium


CVE-ID: CVE-2021-3671

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No


The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the way samba kerberos server handles missing sname attribute in TGS-REQ (Ticket Granting Server - Request). A remote authenticated user can send a specially crafted request to the samba server and perform a denial of service (DoS) attack.


Install updates from vendor's website.

Vulnerable software versions

Samba: 4.14.0 - 4.14.7, 4.13.0 - 4.13.11

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

How the attacker can exploit this vulnerability?

Is there known malware, which exploits this vulnerability?