CVE-2018-18556

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.

• http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
• https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-for-operator-users/Exploit, Third Party Advisory
• https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-next-releasesExploit, Vendor Advisory
• http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
• https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-for-operator-users/Exploit, Third Party Advisory
• https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-next-releasesExploit, Vendor Advisory

Published

Dec 17, 2018

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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