In Apache SpamAssassin before 3.4.5, malicious rule configuration (.cf) files can be configured to run system commands without any output or errors. With this, exploits can be injected in a number of scenarios. In addition to upgrading to SA version 3.4.5, users should only use update channels or 3rd party .cf files from trusted places.
Created spamassassin tracking bugs for this issue:
Affects: fedora-all [bug 1943277]
This vulnerability can only be exploited through a malicious rule configuration file. If you are using third-party rule configuration files, it is important to ensure they come only from trusted sources, or are inspected prior to deployment. Even in the absence of this vulnerability, malicious rule configurations could cause significant disruptions to email processed by SpamAssassin.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2021:4315 https://access.redhat.com/errata/RHSA-2021:4315
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):