CVE-2025-66038 OpenSC越界读取漏洞

/* * PoC Concept for CVE-2025-66038 * This C code demonstrates the condition that triggers the vulnerability. */ #include <stdio.h> #include <stdlib.h> // Mocking the vulnerable function signature int sc_compacttlv_find_tag_vulnerable(const unsigned char *buf, size_t buflen, unsigned int tag_in, const unsigned char **buf_out, size_t *len_out) { // Simplified vulnerable logic if (buflen < 1) return -1; unsigned char first_byte = buf[0]; unsigned char current_tag = first_byte >> 4; unsigned char current_len = first_byte & 0x0F; if (current_tag == tag_in) { // VULNERABILITY: Does not check if current_len fits in (buflen - 1) *buf_out = buf + 1; *len_out = current_len; return 0; // Success } return -1; // Not found } int main() { // Malicious input: Tag 0x0, Length 10 (0xA), but buffer size is only 1 byte unsigned char malicious_buffer[] = {0x0A}; const unsigned char *result_ptr = NULL; size_t result_len = 0; printf("Attempting to parse malicious buffer...\n"); int ret = sc_compacttlv_find_tag_vulnerable(malicious_buffer, sizeof(malicious_buffer), 0x00, &result_ptr, &result_len); if (ret == 0) { printf("Tag found. Pointer: %p, Length: %zu\n", result_ptr, result_len); // The following access would cause an out-of-bounds read // printf("Value: %x\n", *result_ptr); printf("Out-of-bounds read prevented in this demo.\n"); } return 0; }