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.
(cherry picked from commit 997c017df937ea47d999d9724e247c3d0e38e509)
Limit the number of events raised from an SSL record with content_type
alert (21) to a configurable maximum number (default 10). For TLS 1.3,
the limit is set to 1 as specified in the RFC. Add a new weird cases
where the limit is exceeded.
OSS-Fuzz managed to generate a reproducer that raised ~660k ssl_plaintext
and ssl_alert events given ~810kb of input data. This change prevents this
with hopefully no negative side-effect in the real-world.
On Linux with a default ext4 or tmpfs filesystem, the default buffer size for
reading a pcap is chosen as 4k (strace/gdb validated). When reading large pcaps
containing raw data transfers, the syscall overhead for read becomes visible
in profiles. Support configurability of the buffer size and default to 128kb.
When processing a ~830M PCAP (16 UDP connections, each transferring ~50MB) in
bare mode, this change improves runtime from 1.39 sec to 1.29 sec. Increasing
the buffer further didn't provide a noticeable boost.
* origin/topic/awelzel/3145-dcerpc-state-clean:
dce-rpc: Test cases for unbounded state growth
dce-rpc: Handle smb2_close_request() in scripts
smb/dce-rpc: Cleanup DCE-RPC analyzers when fid is closed and limit them
dce-rpc: Do not repeatedly register removal hooks
Roughly 2.5 years ago all events taking the ``icmp_conn`` parameter were
removed with 44ad614094 and the NetVar.cc
type not populated anymore.
Remove the left-overs in script land, too.
This patch does two things:
1) For SMB close requests, tear down any associated DCE-RPC
analyzer if one exists.
2) Protect from fid_to_analyzer_map growing unbounded by introducing a
new SMB::max_dce_rpc_analyzers limit and forcefully wipe the
analyzers if exceeded. Propagate this to script land as event
smb_discarded_dce_rpc_analyzers() for additional cleanup.
This is mostly to fix how the binpac SMB analyzer tracks individual
DCE-RPC analyzers per open fid. Connections that re-open the same or
different pipe may currently allocate unbounded number of analyzers.
Closes#3145.
When a JSON document contains key names containing colons or other
special characters that are not valid in Zeek identifiers, from_json()
cannot be used to parse such input.
This change allows a customizable normalization function.
Closes#3142.
Using break in either of the hooks allows to suppress the default reporter
error message rather than suppressing solely based on the existence of an
assertion_failure() handler.
This reflects the `spicy-plugin` code as of `d8c296b81cc2a11`.
In addition to moving the code into Zeek's source tree, this comes
with a couple small functional changes:
- `spicyz` no longer tries to infer if it's running from the build
directory. Instead `ZEEK_SPICY_LIBRARY` can be set to a custom
location. `zeek-set-path.sh` does that now.
- ZEEK_CONFIG can be set to change what `spicyz -z` print out. This is
primarily for backwards compatibility.
Some further notes on specifics:
- We raise the minimum Spicy version to 1.8 (i.e., current `main`
branch).
- Renamed the `compiler/` subdirectory to `spicyz` to avoid
include-path conflicts with the Spicy headers.
- In `cmake/`, the corresponding PR brings a new/extended version of
`FindZeek`, which Spicy analyzer packages need. We also now install
some of the files that the Spicy plugin used to bring for testing,
so that existing packages keep working.
- For now, this all remains backwards compatible with the current
`zkg` analyzer templates so that they work with both external and
integrated Spicy support. Later, once we don't need to support any
external Spicy plugin versions anymore, we can clean up the
templates as well.
- All the plugin's tests have moved into the standard test suite. They
are skipped if configure with `--disable-spicy`.
This holds off on adapting the new code further to Zeek's coding
conventions, so that it remains easier to maintain it in parallel to
the (now legacy) external plugin. We'll make a pass over the
formatting for (presumable) Zeek 6.1.
* amazing-pp/topic/fupeng/from_json_bif:
Implement from_json bif
Minor updates during merge: Moved ValFromJSON into zeek::detail for the
time being, removed gotos, normalized some error messages to lower case,
minimal test extension and added a raw reader input framework test reading
"json lines" as a demo, adding notes about the implicit type
conversions.
Users on Slack observed memory growth in an environment with a lot of
SMB traffic. jeprof memory profiling pointed at the offset and fid maps
kept per-connection for smb2 read requests.
These maps can grow unbounded if responses are seen before requests, there's
packet drops, just one side of the connection is visible, or we fail to parse
responses properly.
Forcefully wipe out these maps when they grow too large and raise
smb2_discarded_messages_state() to notify script land about this.
For low-level packet analysis use-cases, these fields are currently
not script-land accessible via raw_packet() or so. They are accessible
on the icmp_context record, but not on the actual ip4_hdr record, so
add them.
"Community ID" has become an established flow hash for connection correlation
across different monitoring and storage systems. Other NSMs have had native
and built-in support for Community ID since late 2018. And even though the
roots of "Community ID" are very close to Zeek, Zeek itself has never provided
out-of-the-box support and instead required users to install an external plugin.
While we try to make that installation as easy as possible, an external plugin
always sets the bar higher for an initial setup and can be intimidating.
It also requires a rebuild operation of the plugin during upgrades. Nothing
overly complicated, but somewhat unnecessary for such popular functionality.
This isn't a 1:1 import. The options are parameters and the "verbose"
functionality has been removed. Further, instead of a `connection`
record, the new bif works with `conn_id`, allowing computation of the
hash with little effort on the command line:
$ zeek -e 'print community_id_v1([$orig_h=1.2.3.4, $orig_p=1024/tcp, $resp_h=5.6.7.8, $resp_p=80/tcp])'
1:RcCrCS5fwYUeIzgDDx64EN3+okU
Reference: https://github.com/corelight/zeek-community-id/
Increasing this value 10x has lowered CPU usage on a Myricom based
deployment significantly with reportedly no adverse side-effects.
After reviewing the Zeek 3 IO loop, my hunch is that previously when
no packets were available, we'd sleep 20usec every loop iteration after
calling ->Process() on the packet source. With current master ->Process()
is called 10 times on a packet source before going to sleep just once
for 20 usec. Likely this explains the increased CPU usage reported.
It's probably too risky to increase the current value, so introduce
a const &redef value for advanced users to tweak it. A middle ground
might be to lower ``io_poll_interval_live`` to 5 and increase the new
``Pcap::non_fd_timeout`` setting to 100usec.
While this doesn't really fix#2296, we now have enough knobs for tweaking.
Closes#2296.
Add a central place where the decision when it's okay to update network time
to the current time (wallclock) is. It checks for pseudo_realtime and packet
source existence as well as packet source idleness.
A new const &redef allows to completely disable forwarding of network time.
This probably should not be changed by users, but it's useful for
testing and experimentation rather than needing to recompile.
Processing 100 packets without checking an FD based IO source can
actually mean that FD based sources are never checked during a read
of a very small pcap...
Parse authentic data (AD) and checking disabled (CD) bits according to
RFC 2535. Leaves the Z field as-is, in case users are already handling
this elsewhere and depend on the value being the integer for all 3 bits.
https://www.rfc-editor.org/rfc/rfc2535#section-6.1Fixes#2672
It wasn't possible from script land to determine the total size
of the cache table held by the DNS_Mgr. Add the total and also
also the TEXT entries count.
This change exposes the signature tyope inside the signed portion of an
X.509 certificate. In the past, we only exposed the signature type that
is contained inside the signature, which is outside the signed portion
of the X.509 certificate.
In theory, both signature fields should have the same value; it is,
however, possible to encode differing values in both fields. The new
field is not logged by default.
b41a4bf06d removed a field from this record
because it had a duplicate name as another field. The field does need to
exist, but it needs the correct name.
When disabling_analyzer() was introduced, it was added to the GLOBAL
module. The awkward side-effect is that implementing a hook handler
in another module requires to prefix it with GLOBAL. Alternatively, one
can re-open the GLOBAL module and implement the handler in that scope.
Both are not great, and prefixing with GLOBAL is ugly, so move the
identifier to the Analyzer module and ask users to prefix with Analyzer.
Commit 58fae22708 removed the max_expire==0
handling from DoAdvance() due to not being obvious what use it is. Jan
later reported that it broke the `redef max_timer_expires=0` (#2514).
This commit adds back the special case re-introducing the `max_timer_expires=0` ,
trying to make it fairly explicit that it exists.
This is an adaption of #2516 not adding a new option and trying a bit
to avoid global variable accesses down in DoAdvance(), though that
just moved to InitPostScript().
Fixes#2514.
oss-fuzz produced FTP traffic with a ~550KB long FTP command. Cap FTP command
length at 100 bytes, log a weird if a command is larger than that and move
on to the next. Likely it's not actual FTP traffic, but raising an
analyzer violation would allow clients an easy way to disable the analyzer
by sending an overly long command.
The added test PCAP was generated using a fake Python socket server/client.
Introduce two new events for analyzer confirmation and analyzer violation
reporting. The current analyzer_confirmation and analyzer_violation
events assume connection objects and analyzer ids are available which
is not always the case. We're already passing aid=0 for packet analyzers
and there's not currently a way to report violations from file analyzers
using analyzer_violation, for example.
These new events use an extensible Info record approach so that additional
(optional) information can be added later without changing the signature.
It would allow for per analyzer extensions to the info records to pass
analyzer specific info to script land. It's not clear that this would be
a good idea, however.
The previous analyzer_confirmation and analyzer_violation events
continue to exist, but are deprecated and will be removed with Zeek 6.1.
