A symlink following vulnerability was found in the ABRT post-create event handler scripts in libreport. Event scripts write output files using shell redirections without the O_NOFOLLOW flag. If the target file is replaced with a symlink, the shell process running as root follows the symlink and writes content to the symlink target, allowing arbitrary file overwrites on the system.
The following practices would help for avoiding exposure and mitigate this flaw:
- Disable or remove ABRT if it is not required. On RHEL 8 systems where ABRT is installed, it can be disabled with: systemctl disable --now abrtd.service abrt-journal-core.service abrt-oops.service abrt-xorg.service
- On Fedora systems, consider using systemd-coredump instead of ABRT for crash handling
- Restrict local user access to systems running ABRT, as this vulnerability requires local access
Exploits
Credits
Red Hat would like to thank Red Team (Deutsche Telekom Security GmbH) for reporting this issue.