Vulnerability identifier: #VU24745

Vulnerability risk: Critical

CVSSv3.1: 9.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2020-7247

CWE-ID: CWE-78

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
OpenSMTPD
Server applications / Mail servers

Vendor: OpenBSD

Description

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

The vulnerability exists due to improper validation of user-supplied input passed within the smtp_mailaddr() function. A remote unauthenticated attacker can send a specially crafted MAIL FROM command and execute arbitrary OS commands on the target system with root privileges.

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

Mitigation
Install updates from vendor's website.

Vulnerable software versions

OpenSMTPD: 6.4.0 - 6.6.1p1

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External links
http://seclists.org/oss-sec/2020/q1/40

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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?

Yes. This vulnerability is being exploited in the wild.