NRDAX-T0023 - Coalesced Packet Buffer Leak

memory_amp · active · first seen 2026-07-11

provenance: Reproduced in NullRabbit's attack-reproduction pipeline

mechanism

QUIC-LEAK / CVE-2025-54939: LSQUIC pre-handshake `packet_in` memory leak from coalesced Initial packets (CVSS 7.5 AV:N/AC:L/PR:N/UI:N/A:H, CWE-401+CWE-770; affected LSQUIC < 4.3.1, fixed 4.3.1 / OpenL

instances (1)

chain	primitive	fidelity	origin	reproducer (bundle)	source
quic	lsquic_initial_prehandshake_leak	lab	reverse-engineered-cve	lsquic_initial_prehandshake_leak	CVE-2025-54939 (QUIC-LEAK) — Imperva disclosure (https://www.imperva.com/blog/quic-leak-cve-2025-54939-new-high-risk-pre-handshake-remote-denial-of-service-in-lsquic-quic-implementation/); LiteSpeed advisory https://blog.litespeedtech.com/2025/08/18/litespeed-security-update/. LSQUIC ('LiteSpeed QUIC (LSQUIC) Library LSQUIC Engine Packet In Memory Leak') coalesces multiple QUIC packets per UDP datagram and allocates one ~96-byte `packet_in` per coalesced packet; when trailing coalesced Initial packets fail DCID validation, `lsquic_engine.c` frees only the first packet's `packet_in` and never calls `lsquic_mm_put_packet_in` for the rest -> pre-handshake memory leak that bypasses all post-handshake connection/stream/flow limits -> OOM (~70% of bandwidth).

related (memory_amp)

NRDAX-T0025 - Compact Block Size Integer Overflow active NRDAX-T0038 - Count Underflow Header Serving Amplification active NRDAX-T0042 - Crypto Frame Reassembly Buffer Exhaustion active NRDAX-T0046 - Decompression Bomb Resource Exhaustion active NRDAX-T0059 - Duplicate Transport Parameter Memory Leak active NRDAX-T0061 - Duplicate Tx Mempool Index Desync active NRDAX-T0071 - Ethash Verification Memory Exhaustion active NRDAX-T0095 - GraphQL Alias Query Amplification active

cite

https://nrdax.com/techniques/NRDAX-T0023

plain

NRDAX Registry. Technique NRDAX-T0023.

bibtex

@misc{nrdax_NRDAX_T0023,
  title = {Coalesced Packet Buffer Leak (NRDAX-T0023)},
  howpublished = {NRDAX Registry},
  url = {https://nrdax.com/techniques/NRDAX-T0023},
}

json (csl)

{
  "id": "nrdax-NRDAX-T0023",
  "type": "dataset",
  "title": "Coalesced Packet Buffer Leak (NRDAX-T0023)",
  "URL": "https://nrdax.com/techniques/NRDAX-T0023",
  "publisher": "NRDAX Registry"
}