Optimize the CWE-502 document

[JerryTasi]

Detect CWE-502 in Android Application

This scenario seeks to find Deserialization of Untrusted Data in the APK file.

CWE-502: Deserialization of Untrusted Data

We analyze the definition of CWE-502 and identify its characteristics.

See CWE-502 for more details.

Code of CWE-502 in pivaa.apk

We use the pivaa.apk sample to explain the vulnerability code of CWE-502.

Quark Script CWE-502.py

Let’s use the above APIs to show how the Quark script finds this vulnerability.

To begin with, we created a detection rule named deserializeData.json to identify behaviors that deserialize data.

Next, we retrieve the methods that interact with the deserialization API. Following this, we check if there are any of the APIs in verificationApis are found.

If NO, it could imply that the APK deserializes the untrusted data, potentially leading to a CWE-502 vulnerability.

from quark.script import runQuarkAnalysis, Rule

SAMPLE_PATH = "pivaa.apk"
RULE_PATH = "deserializeData.json"

ruleInstance = Rule(RULE_PATH)

result = runQuarkAnalysis(SAMPLE_PATH, ruleInstance)

verificationApis = [
    ["Ljava/io/File;", "exists", "()Z"],
    ["Landroid/content/Context;", "getFilesDir", "()Ljava/io/File;"],
    ["Landroid/content/Context;", "getExternalFilesDir", "(Ljava/lang/String;)Ljava/io/File;"],
    ["Landroid/os/Environment;", "getExternalStorageDirectory", "()Ljava/io/File;"],
]

for dataDeserialization in result.behaviorOccurList:
    apis = dataDeserialization.getMethodsInArgs()
    caller = dataDeserialization.methodCaller
    if not any(api in apis for api in verificationApis):
        print(f"CWE-502 is detected in method, {caller.fullName}")

Quark Rule: deserializeData.json

{
    "crime": "Deserialize Data",
    "permission": [],
    "api": [

        {
            "class": "Ljava/io/ObjectInputStream;",
            "method": "<init>",
            "descriptor": "(Ljava/io/InputStream;)V"
        },
        {
            "class": "Ljava/io/ObjectInputStream;",
            "method": "readObject",
            "descriptor": "()Ljava/lang/Object;"
        }

    ],
    "score": 1,
    "label": []
}

Quark Script Result

$ python CWE-502.py
CWE-502 is detected in method, Lcom/htbridge/pivaa/handlers/ObjectSerialization; loadObject ()V

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.73%. Comparing base (cf53748) to head (9c73e10).

❗ Current head 9c73e10 differs from pull request most recent head d210c91

Please upload reports for the commit d210c91 to get more accurate results.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #656   +/-   ##
=======================================
  Coverage   78.73%   78.73%           
=======================================
  Files          64       64           
  Lines        5324     5324           
=======================================
  Hits         4192     4192           
  Misses       1132     1132           

Flag	Coverage Δ
unittests	78.73% <ø> (ø)

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[sidra-asa]

LGTM