CVE-2018-7169 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 t...
MediumCVSS 5.3
EPSS 1.6%
- Published
- Updated
- Exploit status
- No public exploit known
Description
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.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| debian/shadow(Debian:12) | < 1:4.7-1 | 1:4.7-1 |
| debian/shadow(Debian:13) | < 1:4.7-1 | 1:4.7-1 |
| debian/shadow(Debian:14) | < 1:4.7-1 | 1:4.7-1 |
| shadow project shadow | = 4.5 | No fix listed |
References
- Debian Security Tracker CVE-2018-7169 vendor-advisory
- bugs.launchpad.net exploit issue-tracking third-party-advisory
- GLSA-201805-09 third-party-advisory vendor-advisory
- bugs.debian.org issue-tracking