Suricata DCERPC: unbounded fragment buffering leads to memory exhaustion

Suricata is a network IDS, IPS and NSM engine. Prior to versions 8.0.3 and 7.0.14, crafted DCERPC traffic can cause Suricata to expand a buffer w/o limits, leading to memory exhaustion and the process getting killed. While reported for DCERPC over UDP, it is believed that DCERPC over TCP and SMB are also vulnerable. DCERPC/TCP in the default configuration should not be vulnerable as the default stream depth is limited to 1MiB. Versions 8.0.3 and 7.0.14 contain a patch. Some workarounds are available. For DCERPC/UDP, disable the parser. For DCERPC/TCP, the `stream.reassembly.depth` setting will limit the amount of data that can be buffered. For DCERPC/SMB, the `stream.reassembly.depth` can be used as well, but is set to unlimited by default. Imposing a limit here may lead to loss of visibility in SMB.