If the tcsd daemon is started with root privileges, the creation of the system.data file is prone to symlink attacks. The tss user can be used to create or corrupt existing files, which could possibly lead to a DoS attack.
Created trousers tracking bugs for this issue:
Affects: fedora-all [bug 1870053]
Upstream commit for this issue:
When tcsd starts it opens the system.data file, however it doesn't check if it already exists as a symbolic link. An attack can leverage that to force tcsd to overwrite any previous existing file, causing data corruption and possible DoS.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2021:1627 https://access.redhat.com/errata/RHSA-2021:1627
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):