NRDAX-T0064 - Endpoint Concurrency Cap Exhaustion

connection_exhaustion · active · first seen 2026-07-04

provenance: Reproduced in NullRabbit's attack-reproduction pipeline

mechanism

cosmos-sdk server/grpc/server.go grpc.NewServer w/o grpc.MaxConcurrentStreams -> grpc-go default effectively unbounded + no SETTINGS_MAX_CONCURRENT_STREAMS signalled; attacker holds many HTTP/2 stream

instances (5)

chain	primitive	fidelity	origin	reproducer (bundle)	source
cosmos	cosmos_grpc_stream_flood	lab	NullRabbit Labs	cosmos_grpc_stream_flood	-
http2	http2_settings_ack_stream_cap_bypass	lab	reverse-engineered-cve	http2_settings_ack_stream_cap_bypass	-
ic	ic_xnet_concurrency_cap	lab	NullRabbit Labs	ic_xnet_concurrency_cap	github.com ↗
iota	iota_grpc_stream_cap_dos	lab	NullRabbit Labs	iota_grpc_stream_cap_dos	-
kaspa	kaspa_grpc_h2_preauth_stream_flood	lab	NullRabbit Labs	kaspa_grpc_h2_preauth_stream_flood	KAS-H1 measured 2026-06-02; connection_handler.rs:222

references

vendor-advisory: GHREL-near-nearcore-1.0.0

related (connection_exhaustion)

NRDAX-T0041 - Cross-Chain Peer Pool Pollution active NRDAX-T0088 - GetData Request Flood active NRDAX-T0099 - Half-Open Handshake Slowloris active NRDAX-T0100 - Handshake Crypto CPU Burn active NRDAX-T0145 - Malformed HTTP Body Crash active NRDAX-T0206 - Pre-Handshake Packet Flood active NRDAX-T0214 - Protocol Message Flood Unbounded Goroutine active NRDAX-T0225 - QUIC Control Frame Flood active

cite

https://nrdax.com/techniques/NRDAX-T0064

plain

NRDAX Registry. Technique NRDAX-T0064.

bibtex

@misc{nrdax_NRDAX_T0064,
  title = {Endpoint Concurrency Cap Exhaustion (NRDAX-T0064)},
  howpublished = {NRDAX Registry},
  url = {https://nrdax.com/techniques/NRDAX-T0064},
}

json (csl)

{
  "id": "nrdax-NRDAX-T0064",
  "type": "dataset",
  "title": "Endpoint Concurrency Cap Exhaustion (NRDAX-T0064)",
  "URL": "https://nrdax.com/techniques/NRDAX-T0064",
  "publisher": "NRDAX Registry"
}