CVE-2018-18556

critical

Description

A privilege escalation issue was discovered in VyOS 1.1.8. The default configuration also allows operator users to execute the pppd binary with elevated (sudo) permissions. Certain input parameters are not properly validated. A malicious operator user can run the binary with elevated permissions and leverage its improper input validation condition to spawn an attacker-controlled shell with root privileges.

References

https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-next-releases

https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-for-operator-users/

http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escalation.html

Details

Source: Mitre, NVD

Published: 2018-12-17

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 9.9

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.15411