DCERPC parsers had no upper bounds when it came to extending the stub
data buffer. Traffic can be crafted to bypass some internal parser
conditions to create an indefinite buffering in the stub_data array that
can make Suricata crash.
Add a default limit of 1MiB and make it configurable for the user.
Security 8182
Co-authored-by: Philippe Antoine <pantoine@oisf.net>
16384 is used as the max, but a configuration parameter has been
provided. The reason for setting an upper bound is that bit flags can
create a memory amplification as we parse them into individual data
structures.
Ticket: #8181
Lower the number of unreplied requests from 500 to 32 to consider a
flood. At the very least this is an anomaly given the DNP3 spec mentions
that DNP3 should only have one outstanding request at a time, with an
exception for unsolicited responses, so in practice no more than 2
should be seen.
Additionally make this value configurable by introducing the max-tx
parameter.
Ticket: #8181
Complete is a flag used to tell if the message was completely parsed,
as not all messages may be completely parsed if we don't know all
their objects. However, they are still "done".
In the alstate-progress callback, check the done flag, not the
complete flag.
Ticket: #8181
Ticket: 8201
Limits the quadratic complexity if each packet, restarting the
header parsing, just adds a new folded line.
This was previously bounded by the configurable max header length
So far, the alert queue was expanded by doubling in size w/o any
boundary checks in place. This led to situations where doubling
the alert_queue_capacity meant overflow of the very same value
stored in det_ctx.
This led to heap-use-after-free in some conditions where
det_ctx->alert_queue_capacity overflowed.
Fix this by capping the max of alert_queue_capacity by checking if its
expansion could result in an overflow.
Security 8190
Ticket: 8156
In case of non-tx alerts, we try to loop over all the txs to find
the xff header. Do not start from tx_id 0, but from min_id
as AppLayerParserTransactionsCleanup to skip txs that were freed
TLS parsers use x509-parser crate which parses X.509 certificates that
use ASN.1 DER encoding that can allow arbitrary byte sequences. An
attacker could inject null byte in a certificate anywhere to stump the
common language parsers terminating the string at a null byte leading to
a bypass of a possibly malicious certificate.
So far, the rust TLS parser for "subjectaltname" used a pattern that involved:
-> Get ASN.1 DER encoded raw data from the x509-parser crate
-> Convert this raw data to a decoded string (Rust)
-> Convert the Rust string to CString
-- The problem lies here. CString only accepts proper strings/byte
buffers and converts it into an owned C-compatible, null-terminated
string. However, if any null byte occurs in the string passed to the
CString then it panics.
In the rust TLS parser, this panic is handled by returning NULL.
This means that the parser will error out during the decoding of the
certificate. However, Suricata must be able to detect the null byte
injection attack being an IDS/IPS.
Hence, replace all such string patterns w.r.t. TLS SAN with a byte
array.
Bug 7887
TLS parsers use x509-parser crate which parses X.509 certificates that
use ASN.1 DER encoding that can allow arbitrary byte sequences. An
attacker could inject null byte in a certificate anywhere to stump the
common language parsers terminating the string at a null byte leading to
a bypass of a possibly malicious certificate.
So far, the rust TLS parser for "issuerdn" used a pattern that involved:
-> Get ASN.1 DER encoded raw data from the x509-parser crate
-> Convert this raw data to a decoded string (Rust)
-> Convert the Rust string to CString
-- The problem lies here. CString only accepts proper strings/byte
buffers and converts it into an owned C-compatible, null-terminated
string. However, if any null byte occurs in the string passed to the
CString then it panics.
In the rust TLS parser, this panic is handled by returning NULL.
This means that the parser will error out during the decoding of the
certificate. However, Suricata must be able to detect the null byte
injection attack being an IDS/IPS.
Hence, replace all such string patterns w.r.t. TLS IssuerDN with a byte
array.
Bug 7887
TLS parsers use x509-parser crate which parses X.509 certificates that
use ASN.1 DER encoding that can allow arbitrary byte sequences. An
attacker could inject null byte in a certificate anywhere to stump the
common language parsers terminating the string at a null byte leading to
a bypass of a possibly malicious certificate.
So far, the rust TLS parser for "Subject" used a pattern that involved:
-> Get ASN.1 DER encoded raw data from the x509-parser crate
-> Convert this raw data to a decoded string (Rust)
-> Convert the Rust string to CString
-- The problem lies here. CString only accepts proper strings/byte
buffers and converts it into an owned C-compatible, null-terminated
string. However, if any null byte occurs in the string passed to the
CString then it panics.
In the rust TLS parser, this panic is handled by returning NULL.
This means that the parser will error out during the decoding of the
certificate. However, Suricata must be able to detect the null byte
injection attack being an IDS/IPS.
Hence, replace all such string patterns w.r.t. TLS Subject with a byte
array.
Bug 7887
When FlowSwap() reverses the direction of a flow, the MAC address sets
stored in the flow also need to be swapped to maintain consistency with
the new direction. Previously, MAC addresses were not swapped along with
other flow properties like packet/byte counters.
Ticket #8172
Make sure the script can use all bytes configured. So exclude setup like
input buffers that are put on the lua state before script is executed.
Bug #8173.
Expose elephant flow flags on a flow via rule language. The rule keyword
is defined as "flow.elephant: <dir>;" where the <dir> can expand to:
- toserver
- toclient
- either
- both
Feature 8117
The tracking for elephant flow is done per direction however, the flag
was set on the flow whenever either of the directions crossed the
rate-limit defined in the settings. Given that the tracking was already
split, it makes sense to split the detection tracking per direction as
well and allow user to have a better control via rule language.
The functionality of "both" can already be easily achieved by using both
"toclient" and "toserver" in a rule. This just adds the ease of
expression in rule. As it is added now, check the direction for the
pre-existing users of direction as well.
Detection and logging skip a lot of work if PKT_STREAM_EST is not set. When
a TFO packet with data comes in the TCP state is not yet established, but
the data still needs to be considered.
So for this case set the PKT_STREAM_EST flag.
Bug #6744.
Philippe Antoine
Shivani Bhardwaj
Jason Ish
Victor Julien
Shivani Bhardwaj
dependabot[bot]
Lukas Sismis
Giuseppe Longo