Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-16 05:28:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

MIME: Cap nested MIME analysis depth to 100

Browse source 
OSS-Fuzz managed to produce a MIME multipart message construction with
thousands of nested entities (or that's what Zeek makes out of it anyhow).
Prevent such deep analysis by capping at a nesting depth of 100,
preventing unnecessary resource usage. A new weird named exceeded_mime_max_depth
is reported when this limit is reached.

This change reduces the runtime of the OSS-Fuzz reproducer from ~45 seconds
to ~2.5 seconds.

The test PCAP was produced from a Python script using the email package
and sending the rendered version via POST to a HTTP server.

Closes #208
This commit is contained in:
Arne Welzel 2024-01-15 21:06:24 +01:00 • committed by Tim Wojtulewicz
parent cea7c473ac
commit 2a858d252e
13 changed files with 74 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

11
testing/btest/Baseline/scripts.base.protocols.http.deeply-nested-mime/weird.log Normal file
View file

@ -0,0 +1,11 @@
### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
#separator \x09
#set_separator ,
#empty_field (empty)
#unset_field -
#path weird
#open XXXX-XX-XX-XX-XX-XX
#fields ts uid id.orig_h id.orig_p id.resp_h id.resp_p name addl notice peer source
#types time string addr port addr port string string bool string string
XXXXXXXXXX.XXXXXX CHhAvVGS1DHFjwGM9 127.0.0.1 48724 127.0.0.1 8080 exceeded_mime_max_depth 100 F zeek HTTP
#close XXXX-XX-XX-XX-XX-XX