#VU15169 OS Command Injection in Mgetty+Sendfax - CVE-2018-16741

Vulnerability identifier: #VU15169

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-16741

CWE-ID: CWE-78

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Mgetty+Sendfax
Client/Desktop applications / Other client software

Vendor: EDV-Beratung Gert Döring

Description

The vulnerability allows a local user to execute arbitrary shell commands on the target system.

The vulnerability exists within mgetty before 1.2.1. In fax/faxq-helper.c, the function do_activate() due to improper sanitization of shell metacharacters. A local user can use ||, &&, or > characters within a file created by the "faxq-helper activate <jobid>" command to execute arbitrary OS commands on the target system.

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

Mitigation
Install update from vendor's website.

Vulnerable software versions

Mgetty+Sendfax: 1.2.0

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External links
https://lists.debian.org/debian-lts-announce/2018/09/msg00012.html
https://www.debian.org/security/2018/dsa-4291
https://www.x41-dsec.de/lab/advisories/x41-2018-007-mgetty

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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