#VU51702 Heap-based buffer overflow in Samba - CVE-2020-27840

Vulnerability identifier: #VU51702

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-27840

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

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

Vendor: Samba

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing DNs inside bind requests. A remote attacker can send specially crafted LDAP request to Samba AD DC LDAP server, trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Samba: 4.0.0 - 4.0.26, 4.1.0 - 4.14.0, 4.2.0 - 4.2.14, 4.3.0 - 4.3.13, 4.4.0 rc4 - 4.4.16, 4.5.0 - 4.5.16, 4.6.0 - 4.6.16, 4.7.0 - 4.7.12, 4.8.0 - 4.8.12, 4.9.0 - 4.9.18

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External links
https://www.samba.org/samba/security/CVE-2020-27840.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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