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.

CVSS v3.1

9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS v2.0

9.0 HIGHAV:N/AC:L/Au:S/C:C/I:C/A:C

EPSS

15.41% chance of exploitation in the next 30 days, 97th percentile

Published

2018-12-17

Updated

2024-08-05

Proof-of-concept exploits (3)

• http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escala…
• https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-f…
• https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-nex…

Metasploit modules (1)

• rapid7/metasploit-framework/blob/master/modules/exploits/linux/ssh/vyos_restricted_shell_…

References

• CVE Record
• NVD entry

Related

• CVE-2018-18555
• CVE-2018-18557
• CVE-2018-18552
• CVE-2018-18566
• CVE-2018-18551
• CVE-2018-18567