CVE-2019-17041

An issue was discovered in Rsyslog v8.1908.0.
contrib/pmaixforwardedfrom/pmaixforwardedfrom.c has a heap overflow in the
parser for AIX log messages. The parser tries to locate a log message
delimiter (in this case, a space or a colon) but fails to account for
strings that do not satisfy this constraint. If the string does not match,
then the variable lenMsg will reach the value zero and will skip the sanity
check that detects invalid log messages. The message will then be
considered valid, and the parser will eat up the nonexistent colon
delimiter. In doing so, it will decrement lenMsg, a signed integer, whose
value was zero and now becomes minus one. The following step in the parser
is to shift left the contents of the message. To do this, it will call
memmove with the right pointers to the target and destination strings, but
the lenMsg will now be interpreted as a huge value, causing a heap
overflow.

Bugs

• <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942067&gt;

Notes