CVE-2018-18556
9.9
CRITICAL · CVSS 3.1 · EPSS 15.4% (pctl 97)
Patch early
EPSS 15.4% — above the 10% action threshold.
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.
Scoring
| CVSS | 9.9 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 15.41% — more likely to be exploited than 97% of all CVEs |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2018-12-17 |
| Last modified | 2026-06-17 |
Affected (1)
| Vendor | Product |
|---|---|
| vyos | vyos |
References
- http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escalation.html
- https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-for-operator-users/
- https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-next-releases
- http://packetstormsecurity.com/files/159234/VyOS-restricted-shell-Escape-Privilege-Escalation.html
- https://blog.mirch.io/2018/11/05/cve-2018-18556-vyos-privilege-escalation-via-sudo-pppd-for-operator-users/
- https://blog.vyos.io/the-operator-level-is-proved-insecure-and-will-be-removed-in-the-next-releases
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