Description
In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own arbitrary directory path locations and escalate privileges to root when the guest user logs out.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | lightdm | 1.18.3-0ubuntu1.1 | USN-3255-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- LightDM (Ubuntu 16.04/16.10) - 'Guest Account' Local Privilege Escalation EDB-41923 · local · Apr 25, 2017
GitHub 1 repository
-
JonPichel/CVE-2017-7358 ★ 0 · Feb 25, 2023
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- USN-3255-1 lightdm vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026