Debian update for exim4

1) OS Command Injection

EUVDB-ID: #VU19368

Risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-13917

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

Exploit availability: No

Description

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

The vulnerability exists due to insufficient filtering of user-supplied data under certain conditions, e.g. if your configuration uses the ${sort } expansion. A remote unauthenticated attacker can send a specially crafted email, modify $local_part or $domain items, inject 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 however requires non-default exim configuration.

Mitigation

Update exim4 package to one of the following versions: 4.89-2+deb9u5, 4.92-8+deb10u1.

Vulnerable software versions

exim4 (Debian package): 4.89-2+deb9u1 - 4.89-2+deb9u4

External links

http://www.debian.org/security/2019/dsa-4488

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.