geedge.lantern.io
detection confidence: medium public

An internal experiment using BurpSuite as a MITM proxy tests injecting a forged QUIC ServerHello carrying a connection-close frame ahead of the real server response, to make the client abandon its QUIC handshake; the author separately proposes recording every site known to support QUIC and simply blocking plain TCP connections to those sites, on the theory that this indirectly forces QUIC off since a censor cannot otherwise tell in advance which TCP flow would have upgraded to QUIC.

测试通过第三方注入带有连接关闭帧的serverHello,及时关闭客户端发出的quic初始数据包clientHello...如果把所有支持quic的网站都记录下来,屏蔽这些网站的tcp连接(关闭tcp连接),不就也可以关闭通往这些网站的quic连接了吗?

Defense implications

censorscn
capabilityactive-probing-impl

extracted_by: claude-sonnet-5 · added 2026-08-26 · id: 2026-0ee495-quic-serverhello-inject

Related findings

detection

An internal TSG functional-requirements spec ('加密协议JG') defines device support for identifying and blocking ECH, ESNI and QUIC traffic via per-connection SNI/region-matching tables (e.g. DF_QUIC_REGION), plus a companion 'FD报文全流程感知' feature that both passively monitors and actively injects synthetic verification traffic end-to-end through the network path to compute a live per-rule 'CT率' (breakthrough/penetration rate) — the system self-measures how often its own QUIC/ESNI/ECH blocks fail to take effect, and separately throttles logging/blocking detail for rule IDs receiving unusually high hit counts (DF_ATTACK_PROTECTION, 'targeted attack detection').

detection

A MESA Lab thesis/report states that ESNI/ECH protocol-identification technology, based on TLS extension field type numbers, "has already been applied in actual projects," and lists the researcher's own project participation as "G1系统 - ESNI、ECH加密协议识别" (Feb-Aug 2023) and "G1系统 - QUIC协议旁路ZD" (Feb-Nov 2023, QUIC bypass/blocking), plus a separately implemented "DNS主动探测模块" (DNS active-probing module, marked 已实现/already implemented). "G1" also appears independently as a named legacy system in the Maat/Transformer DPI header (PROTO_VPN comment: "G1历史遗留"), corroborating it as a real internal system name, not a typo.

detection

A MESA Lab repo (shihaoyue/yy_deploy_script) contains an organized suite of active attack tooling specifically targeting encrypted DNS: DoH/DoT downgrade attacks, DoH/DoT DDoS including a CVE-2024-4487 (HTTP/2 Rapid Reset) exploit script, IPv6 DNS response spoofing/injection (fakedns6 using forged-source-address "saddns"), a DNSSEC-downgrade proxy, DNSSEC-DDoS tooling, and an active DNS-fingerprinting probe pair (fpdns_client/fpdns_server under a folder named "TargetGZ"). This is direct evidence of GFW-adjacent R&D that specifically attacks the encrypted-DNS protocols (DoH/DoT) circumvention tools often rely on for resolver privacy.

deployment

An internal TSG operations/troubleshooting manual lays out TSG's full traffic pipeline (NIC -> mrzcpd/marsio capture driver -> sapp DPI engine -> firewall/proxy(KNI->TFE)/active-defense/WAN-NAT policy branches) and shows engineers using maat_redis_tool to pull the live Redis-synced blocking policy tables (TSG_SECURITY_COMPILE, TSG_OBJ_IP_ADDR, TSG_OBJ_APP_ID) and filter them by numeric policy/object ID to debug why a block rule isn't firing.

deployment

A 2023 MESA Lab monthly report describes the 'TF' project's active-defense work: test cases for serial ('串联') HTTP hijack/tamper and parallel ('并联') DNS race-injection ('DNS抢答'), performance tuning that scaled active-defense capacity from 3 to 5 units, converting two existing TSG boxes to active-defense mode, and rewriting the active-defense flow-control logic to no longer depend on sapp.

detection

A MESA Lab monthly report states that adjustments to a VPN-detection module accumulated over 10,000 Psiphon3 server IPs and delayed a Psiphon3 client's ability to get online by at least 3 minutes in the researchers' test environment, an earlier-stage data point consistent with the much larger-scale (~70-73K IP) 'vpn-thwarting'/CyberNarrator Psiphon-harvesting pipeline documented elsewhere in this corpus.