Bro 2.5.5 primarily addresses security issues:
- Fix array bounds checking in BinPAC: for arrays
that are fields within a record, the bounds check
was based on a pointer to the start of the record
rather than the start of the array field, potentially
resulting in a buffer over-read.
- Fix SMTP command string comparisons: the number
of bytes compared was based on the user-supplied
string length and can lead to incorrect matches.
e.g. giving a command of "X" incorrectly matched
"X-ANONYMOUSTLS" (and an empty commands match
anything).
Address potential vectors for Denial of Service:
- "Weird" events are now generally suppressed/sampled
by default according to some tunable parameters.
- Improved handling of empty lines in several text
protocol analyzers that can cause performance issues
when seen in long sequences.
- Add `smtp_excessive_pending_cmds' weird which
serves as a notification for when the "pending
command" queue has reached an upper limit and been
cleared to prevent one from attempting to slowly
exhaust memory.