A denial of service vulnerability was found in rsyslog in the imptcp module. An attacker could send a specially crafted message to the imptcp socket, which would cause rsyslog to crash. Versions before 8.27.0 are vulnerable.
imudp in rsyslog 4.x before 4.1.2, 3.21 before 3.21.9 beta, and 3.20 before 3.20.2 generates a message even when it is sent by an unauthorized sender, which allows remote attackers to cause a denial of service (disk consumption) via a large number of spurious messages.
Stack-based buffer overflow in the parseLegacySyslogMsg function in tools/syslogd.c in rsyslogd in rsyslog 4.6.x before 4.6.8 and 5.2.0 through 5.8.4 might allow remote attackers to cause a denial of service (application exit) via a long TAG in a legacy syslog message.