Deserialization of Untrusted Data

Opis

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Inne nazwy

Marshaling/Marshalling, Unmarshaling/Unmarshalling

Marshaling and unmarshaling are effectively synonyms for serialization and deserialization, respectively.

Pickling, Unpickling

In Python, the "pickle" functionality is used to perform serialization and deserialization.

PHP Object Injection

Some PHP application researchers use this term when attacking unsafe use of the unserialize() function; but it is also used for CWE-915.

Skutki

• Integrity

  Modify Application Data; Unexpected State

  Attackers can modify unexpected objects or data that was assumed to be safe from modification. Deserialized data or code could be modified without using the provided accessor functions, or unexpected functions could be invoked.

• Availability

  DoS: Resource Consumption (CPU)

  If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.

• Other

  Varies by Context

  The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation. One example is attackers using gadget chains to perform unauthorized actions, such as generating a shell.

Zapobieganie

• Architecture and Design, Implementation

  If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.

• Implementation

  When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.

• Implementation

  Explicitly define a final object() to prevent deserialization.

• Architecture and Design, Implementation

  Make fields transient to protect them from deserialization.

  An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

• Implementation

  Avoid having unnecessary types or gadgets (a sequence of instances and method invocations that can self-execute during the deserialization process, often found in libraries) available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.

• Architecture and Design, Implementation

  Employ cryptography of the data or code for protection. However, it's important to note that it would still be client-side security. This is risky because if the client is compromised then the security implemented on the client (the cryptography) can be bypassed.

• Operation · Firewall

  Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

  Skuteczność: Moderate

Przykłady podatności

• CVE-2024-37052 insecure deserialization in platform for managing AI/ML applications and models allows code execution via a crafted pickled object in a model file
• CVE-2024-37288 deserialization of untrusted YAML data in dashboard for data query and visualization of Elasticsearch data
• CVE-2024-9314 PHP object injection in WordPress plugin for AI-based SEO
• CVE-2019-12799 chain: bypass of untrusted deserialization issue (CWE-502) by using an assumed-trusted class (CWE-183)
• CVE-2015-8103 Deserialization issue in commonly-used Java library allows remote execution.
• CVE-2015-4852 Deserialization issue in commonly-used Java library allows remote execution.
• CVE-2013-1465 Use of PHP unserialize function on untrusted input allows attacker to modify application configuration.
• CVE-2012-3527 Use of PHP unserialize function on untrusted input in content management system might allow code execution.
• CVE-2012-0911 Use of PHP unserialize function on untrusted input in content management system allows code execution using a crafted cookie value.
• CVE-2012-0911 Content management system written in PHP allows unserialize of arbitrary objects, possibly allowing code execution.
• CVE-2011-2520 Python script allows local users to execute code via pickled data.
• CVE-2012-4406 Unsafe deserialization using pickle in a Python script.
• CVE-2003-0791 Web browser allows execution of native methods via a crafted string to a JavaScript function that deserializes the string.

Słabość nadrzędna

• CWE-913 Improper Control of Dynamically-Managed Code Resources

Pokrewna

• CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes

Kiedy powstaje

• Architecture and Design — OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
• Implementation

Dotyczy

Java, Ruby, PHP, Python, JavaScript, Not Technology-Specific, ICS/OT, AI/ML

Uwagi

The relationships between CWE-502 and CWE-915 need further exploration. CWE-915 is more narrowly scoped to object modification, and is not necessarily used for deserialization.

Źródła

1. The CLASP Application Security Process — Secure Software, Inc., 2005
2. Exploiting Deserialization Vulnerabilities in Java — Matthias Kaiser, 2015
3. PHP unserialization vulnerabilities: What are we missing? — Sam Thomas, 2015
4. Marshalling Pickles: How deserializing objects can ruin your day — Gabriel Lawrence, Chris Frohoff, 2015
5. Unserializing user-supplied data, a bad idea — Heine Deelstra, 2010
6. Black Hat EU 2010 - Attacking Java Serialized Communication — Manish S. Saindane, 2010
7. Why Python Pickle is Insecure — Nadia Alramli, 2009
8. Exploiting misuse of Python's "pickle" — Nelson Elhage, 2011
9. Deserialize My Shorts: Or How I Learned to Start Worrying and Hate Java Object Deserialization — Chris Frohoff, 2016
10. D3FEND: Application Layer Firewall — D3FEND