Vulnerability identifier: #VU66202

Vulnerability risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3670

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Samba
Server applications / Directory software, identity management

Vendor: Samba

Description

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

The vulnerability exists due to Samba AD DC LDAP does not honor the MaxQueryDuration option when handling LDAP requests. A remote user can execute heavy queries and perform a denial of service (DoS) attack.

Mitigation
Vendor does not consider this a security vulnerability and recommends to follow general hardening rules to avoid similar attack vectors.

Vulnerable software versions

Samba: 4.14.3

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External links
http://bugzilla.samba.org/show_bug.cgi?id=14694
http://gitlab.com/samba-team/samba/-/commit/1d5b155619bc532c46932965b215bd73a920e56f

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.