USENIX: WOOT '26 - Protocol Prying: Systematic Vulnerability Research in the AirDrop and Android Quick...

Protocol Prying: Systematic Vulnerability Research in the AirDrop and Android Quick Share Proximity Transfer Protocols

Arash Ale Ebrahim and Nils Ole Tippenhauer, CISPA Helmholtz Center for Information Security

Apple AirDrop and Google/Samsung Quick Share are proximity file-transfer protocols used by over five billion devices, yet their application-layer security properties remain largely unstudied because both stacks are proprietary and undocumented. Both protocols are reachable from wireless proximity without any prior pairing and process complex serialized content (binary plists, CPIO archives, Protocol Buffers, UKEY2handshakes)inside privileged daemons,making them attractive zero-click targets across multiple operating systems. We perform the first cross-platform reverse engineering and protocol-aware fuzzing study of both stacks. We reconstruct AirDrop’s seven-layer state machine and DVZip adaptive compression from binary analysis, build AIRFUZZ, a protocol-aware fuzzer that mutates pre-compression representations, and complement it with targeted hand-written analyses of Samsung’s Quick Share service and Google’s Quick Share for Windows. We discover six vulnerabilities (V1-V6): three pre-authentication issues in macOS/iOS Air Drop (V1: Swift fatalError DoS in the HTTP path router; V2: unbounded XML plist recursion in Foundation, V3: NULL deref in Network.framework’s HTTP/1.1 parser), two protocol-layer flaws in Samsung Quick Share (V4: pre-authentication OfflineFrame dispatch, V5: D2D encryption bypass for three frame types), and a heap use-after-free in Google Quick Share for Windows (V6) for which Google awarded a bounty. We responsibly disclosed all findings, Apple, Samsung, and Google have acknowledged the reports.

View the full WOOT '26 program at https://www.usenix.org/conference/woot26/technical-sessions