CVE-2026-32883 Botan OCSP签名验证缺失漏洞

// PoC Concept: Demonstrating the acceptance of an unsigned OCSP response // This code illustrates the logic flaw present in Botan < 3.11.0 #include <botan/x509cert.h> #include <botan/ocsp.h> #include <vector> void simulate_vulnerable_check() { // 1. Setup: A revoked certificate and its issuer // Botan::X509_Certificate revoked_cert("...path_to_revoked..."); // Botan::X509_Certificate issuer_cert("...path_to_issuer..."); // 2. Forge an OCSP Response // Construct a DER blob indicating status 'GOOD' but signed with a dummy/fake key. std::vector<uint8_t> forged_ocsp_response = { // DER encoded OCSP Response with: // - ResponseStatus: successful // - ResponseBytes: CertStatus = good // - Signature: INVALID or MISSING }; try { // 3. Botan parses the response // In vulnerable versions, signature verification is skipped here. // Botan::OCSP::Response response(forged_ocsp_response); // 4. Check status for the certificate // auto status = response.status_for(revoked_cert, issuer_cert); // 5. Exploit Result // If the library returns OCSP_RESPONSE_GOOD, the vulnerability is confirmed. // The revoked certificate is accepted as valid despite the invalid signature. } catch (std::exception& e) { // Handle parsing or validation errors } }