A time-of-check time-of-use (TOCTOU) race condition was found in the abrt-dbus D-Bus service's SetElement method. Between dump directory creation and post-create event execution, any local user can call SetElement to write arbitrary text files into the root-owned dump directory, bypassing package validation and allowing crashes of unpackaged binaries to survive post-create processing.
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, as ABRT is being phased out in favor of systemd-coredump
- Restrict local user access to systems running ABRT, as this vulnerability requires local access