OS Command Injection in exim (Alpine package)

1) OS Command Injection

EUVDB-ID: #VU20924

Risk: High

CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-15846

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 incorrect processing of trailing backslash during TLS connection. A remote unauthenticated attacker can send specially crafted command via an established TLS connection 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

exim (Alpine package): 4.80.1-r0 - 4.91-r1

External links

http://git.alpinelinux.org/aports/commit/?id=3d8ae8e8d508872200529d643aab4684370ab1de
http://git.alpinelinux.org/aports/commit/?id=2ddca1d1a3d9f54e82951643ad410d21bc73bc19
http://git.alpinelinux.org/aports/commit/?id=39a872f50f0aad285a8d27911f33a2f7d19d564e
http://git.alpinelinux.org/aports/commit/?id=b00e17847dcd3af333f15f9f1f902086d59dc92f

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, proof of concept for this vulnerability is available.