cve/2018/CVE-2018-7169.md

CVE-2018-7169

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.

POC

Reference

No PoCs from references.

Github

• https://github.com/ARPSyndicate/cvemon
• https://github.com/PajakAlexandre/wik-dps-tp02
• https://github.com/andir/nixos-issue-db-example
• https://github.com/flyrev/security-scan-ci-presentation
• https://github.com/garethr/snykout
• https://github.com/nedenwalker/spring-boot-app-using-gradle
• https://github.com/nedenwalker/spring-boot-app-with-log4j-vuln