A 100,000-file leak moves Geedge from suspected censorship vendor to matched Great Firewall part

A team of American academics told this year's USENIX security conference that the Chinese government is running Geedge Networks' Tiangou Secure Gateway as one of the Great Firewall's three known traffic filtering capabilities ^{[1] [2]}. They got there by reconstructing the device's firmware from more than 100,000 files that leaked out of Geedge's own network last year ^[3], which moves the story about Chinese censorship vendors from plausible inference to a named box with matched behaviour.

The leak was not a document dump. It included the databases behind Geedge's Jira and Confluence portals and all of the company's Git source code repositories, with commit history reaching back to November 2024 ^[4]. The researchers used that source and history to rebuild TSG firmware, then compared what the rebuilt filtering code does against observed sections and behaviour of the Great Firewall ^[5]. That is the part worth noting for anyone who does this kind of work: the comparison did not require physical access to a deployed appliance. A complete repository plus commit history is enough to produce an artifact you can characterise, and characterisation is what turns a censorship measurement into an attribution.

The scope claim deserves care. The newsletter reports TSG as one of three known filtering capabilities ^[2], while Bill Marczak noted on August 16, 2026 that Geedge is only one of the vendors involved and that the authors matched just one of the three characterised DNS injectors making up the Great Firewall to Geedge code ^{[6] [7]}. Two of the three injectors, on that account, still belong to somebody whose source code nobody has ^[8].

On engineering quality, the paper is blunt. The authors conclude TSG is as insecure and poorly coded as its Western counterparts ^[9], and write that its complexity and flexibility "are a double-edged sword": core components such as SAPP and its protocol plugins are written in memory-unsafe C, the system still leans on transitional arrangements like Stellar-on-SAPP, and code is copied from several third parties ^[10]. They say the Jira tickets corroborate that patchwork process, citing an AppSketch database upgrade that caused SAPP to restart as evidence of missing code verification ^[10]. The researchers expect the combination of published code, poor quality and abundant bugs to be usable by circumvention tools in future ^[11]. National filtering infrastructure procured as a commercial product inherits commercial defect rates, and a restart-on-upgrade bug in a censorship path is a gap in that path.

The same leak also exposed Geedge's export business, with reports shortly afterwards confirming sales of its censorship tooling to Kazakhstan, Ethiopia, Pakistan and Myanmar ^[12].

Watch whether the other two DNS injectors get attributed to other suppliers, because a three-vendor Great Firewall is a procurement structure rather than a single system, and each vendor is a separate leak risk ^{[7] [8]}. Watch whether circumvention projects publish anything that visibly exploits the reconstructed firmware ^[11]. And watch the export customers: if the same firmware family is deployed in Kazakhstan, Ethiopia, Pakistan or Myanmar, the reconstruction gives researchers a fingerprint to test for outside China ^[12].