CVE-2018-7169
Publication date 15 February 2018
Last updated 25 August 2025
Ubuntu priority
An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used "group blacklisting" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.
Patch details
| Package | Patch details |
|---|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.3 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-5254-1
- shadow vulnerabilities
- 27 January 2022