Patched code sample

import pickle
import pickletools
import io

# The CVE-2026-22612 is fictional. This code demonstrates a hypothetical fix
# for the described vulnerability: "detection bypass due to 'builtins' blindness".
#
# A vulnerable static analyzer would fail to check for dangerous functions
# within the 'builtins' module (like exec, eval). The fix involves
# explicitly adding these built-in functions to the detection logic.


def fixed_pickle_analyzer(pickle_data):
    """
    Represents the patched static analyzer.

    It inspects pickle opcodes for dangerous GLOBAL calls and, unlike the
    vulnerable version, is aware of malicious functions within 'builtins'.
    """
    # The PATCH: The set of dangerous global functions now includes entries
    # from the 'builtins' module, fixing the "blindness".
    DANGEROUS_GLOBALS = {
        ('os', 'system'),
        ('subprocess', 'run'),
        ('builtins', 'eval'),
        ('builtins', 'exec'),
        ('builtins', 'compile'),
    }

    findings = []
    
    # Use pickletools to safely disassemble the pickle into opcodes
    # without executing any code.
    try:
        opcodes = list(pickletools.genops(pickle_data))
    except Exception:
        return ["Analysis failed: Malformed pickle data."]

    for opcode, arg, _ in opcodes:
        # The GLOBAL opcode is used to push a global object (like a function)
        # onto the pickle machine's stack. Its argument is 'module\nname'.
        if opcode.name == 'GLOBAL':
            try:
                module, name = arg.split('\n', 1)
                if (module, name) in DANGEROUS_GLOBALS:
                    findings.append(
                        f"Dangerous global detected: '{module}.{name}'"
                    )
            except (ValueError, AttributeError):
                # Ignore malformed GLOBAL arguments for this example.
                continue
                
    return findings


class MaliciousPayloadOS:
    """Payload that uses a commonly blocked function (os.system)."""
    def __reduce__(self):
        # This will generate a `GLOBAL 'os\nsystem'` opcode.
        import os
        return (os.system, ('echo "[PAYLOAD 1] os.system executed"',))

class MaliciousPayloadBuiltin:
    """
    Payload that uses a built-in function to bypass a "blind" analyzer.
    This is the type of payload the CVE describes.
    """
    def __reduce__(self):
        # This will generate a `GLOBAL 'builtins\nexec'` opcode.
        import builtins
        return (builtins.exec, ('print("[PAYLOAD 2] builtins.exec executed")',))


if __name__ == '__main__':
    # 1. Create a pickle using a standard dangerous function.
    payload_os = pickle.dumps(MaliciousPayloadOS())

    # 2. Create a pickle using a dangerous built-in, exploiting the "blindness".
    payload_builtin = pickle.dumps(MaliciousPayloadBuiltin())

    print("--- Running Patched Analyzer Demonstration ---")
    
    # Test 1: Analyzing the 'os.system' payload.
    # A vulnerable and a patched analyzer would both catch this.
    print("\nAnalyzing payload with 'os.system':")
    findings1 = fixed_pickle_analyzer(payload_os)
    if findings1:
        for finding in findings1:
            print(f"  [!] {finding}")
    else:
        print("  [-] No dangerous globals found.")

    # Test 2: Analyzing the 'builtins.exec' payload.
    # A vulnerable analyzer would find nothing.
    # The fixed analyzer correctly identifies the threat.
    print("\nAnalyzing payload with 'builtins.exec':")
    findings2 = fixed_pickle_analyzer(payload_builtin)
    if findings2:
        for finding in findings2:
            print(f"  [!] {finding}")
    else:
        print("  [-] No dangerous globals found.")