OS Command Injection in opensmtpd (Alpine package)

1) OS Command Injection

EUVDB-ID: #VU24745

Risk: Critical

CVSSv3.1: 9.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2020-7247

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: Yes

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 update from vendor's website.

Vulnerable software versions

opensmtpd (Alpine package): 6.6.4p1-r1

External links

http://git.alpinelinux.org/aports/commit/?id=c79085e53638c5042ab6dfc14708d12f1b8ffd4b
http://git.alpinelinux.org/aports/commit/?id=aa41d4cbc4eb79fa1f3760a6b8f857dfd6f6bf0a
http://git.alpinelinux.org/aports/commit/?id=9ac0e8dd446ac9cf05541dabfe6cc559e8fe5e1c

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. However, a fully functional exploit for this vulnerability is available.