A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module. A crafted input sequence during oversize-frame recovery can cause an invalid internal message length and terminate rsyslogd. No confidentiality or integrity impact, privilege escalation, or code execution has been identified. imtcp and the default imptcp framing modes are not affected.
To mitigate this issue, users that are relying on the imptcp module can implement one of the following options:
1) Remove the framing.delimiter.regex from the affected
2) Disabled the affected imptcp listener or unload imptcp if it's not required
3) Restrict the network access to the listener to trusted senders only