CVE-2018-16741

Description

A command injection flaw was discovered in mgetty in the faxrunq script used to send queued faxes. The shell script faxrunq does not properly escape the arguments passed to faxsend before evaluating the command allowing a user, who has permissions to queue faxes in the system, to execute arbitrary command with elevated privileges.

Mitigation

Allow only trusted users to run the faxq-helper binary, by correctly setting the /etc/mgetty+sendfax/fax.allow configuration file.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.77.8N/A
Attack VectorLocalLocalN/A
Attack ComplexityLowLowN/A
Privileges RequiredHighLowN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityHighHighN/A
Integrity ImpactHighHighN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

CWE-77

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands

If a malicious user injects a character (such as a semi-colon) that delimits the end of one command and the beginning of another, it may be possible to then insert an entirely new and unrelated command that was not intended to be executed. This gives an attacker a privilege or capability that they would not otherwise have.

Frequently Asked Questions

Not sure what something means? Check out our Security Glossary.

Want to get errata notifications? Sign up here.