Ticket: 8513
During decompression, fail early if we have a big decompression
ratio, and enough data.
Track this data also during a tx lifetime, and even a flow/state
lifetime, so that we set event and fail also if the compression
bomb is split over multiple packets
Ticket: 8289
If stream.reassembly.depth is unlimited,
an attacker controlling the 2 sides of a communication going through Suricata
can send a transition with an infinite number of headers, until suricata OOMs
Solution is to offer a configuration option to bound the number
of HTTP2 frames we store in a HTTP2 transaction, and produce an
anomaly if this bound is crossed
Ticket: 7658
Suricata will not handle well if we open a file for this tx,
do not close it, but set the transaction state to completed.
RFC 9113 section 6.1 states:
If a DATA frame is received whose Stream Identifier field is 0x00,
the recipient MUST respond with a connection error (Section 5.4.1)
of type PROTOCOL_ERROR.
Ticket: 5926
HTTP2 continuation frames are defined in RFC 9113.
They allow header blocks to be split over multiple HTTP2 frames.
For Suricata to process correctly these header blocks, it
must do the reassembly of the payload of these HTTP2 frames.
Otherwise, we get incomplete decoding for headers names and/or
values while decoding a single frame.
Design is to add a field to the HTTP2 state, as the RFC states that
these continuation frames form a discrete unit :
> Field blocks MUST be transmitted as a contiguous sequence of frames,
> with no interleaved frames of any other type or from any other stream.
So, we do not have to duplicate this reassembly field per stream id.
Another design choice is to wait for the reassembly to be complete
before doing any decoding, to avoid quadratic complexity on partially
decoding of the data.
http2_parse_var_uint can overflow the variable-length
integer it is decoding. In this case, it now returns an error
of kind LengthValue.
The new function http2_parse_headers_blocks, which factorizes
the code loop for headers, push promise, and continuation, will
check for this specific error, and instead of erroring itself,
will return the list of so far parsed headers, plus another one
with HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeIntegerOverflow
This status is then checked by process_headers to create an
app-layer event.
Philippe Antoine
Philippe Antoine