Vulnerability identifier: #VU16155

Vulnerability risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-16841

CWE-ID: CWE-415

Exploitation vector: Network

Exploit availability: No

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

Vendor: Samba

Description

The vulnerability allows a remote authenticated attacker to cause DoS condition.

The vulnerability exists due to Samba's KDC will call talloc_free() twice on the same memory if the principal in a validly signed certificate does not match the principal in the AS-REQ when configured to accept smart-card authentication. A remote attacker can trigger double-free with talloc_free() and directly calls abort() and cause the KDC process to crash.

Mitigation
The vulnerability has been fixed in the version 4.7.12, 4.8.7, and 4.9.3.

Vulnerable software versions

Samba: 4.7.0 - 4.7.11, 4.8.0 - 4.8.6, 4.9.0 - 4.9.2, 4.6.0 - 4.6.16, 4.5.0 - 4.5.16, 4.4.0 - 4.4.16, 4.3.0 - 4.3.13

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External links
http://www.samba.org/samba/security/CVE-2018-16841.html

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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.