Apple Swift up to 5.6.1 JSON Document type conversion

Summaryinfo

A vulnerability has been found in Apple Swift up to 5.6.1 and classified as problematic. Affected by this issue is some unknown functionality of the component JSON Document Handler. The manipulation leads to type conversion. This vulnerability is uniquely identified as CVE-2022-1642. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apple Swift up to 5.6.1. It has been rated as problematic. This issue affects an unknown part of the component JSON Document Handler. The manipulation with an unknown input leads to a type conversion vulnerability. Using CWE to declare the problem leads to CWE-704. The product does not correctly convert an object, resource, or structure from one type to a different type. Impacted is availability. The summary by CVE is:

A program using swift-corelibs-foundation is vulnerable to a denial of service attack caused by a potentially malicious source producing a JSON document containing a type mismatch. This vulnerability is caused by the interaction between a deserialization mechanism offered by the Swift standard library, the Codable protocol; and the JSONDecoder class offered by swift-corelibs-foundation, which can deserialize types that adopt the Codable protocol based on the content of a provided JSON document. When a type that adopts Codable requests the initialization of a field with an integer value, the JSONDecoder class uses a type-erased container with different accessor methods to attempt and coerce a corresponding JSON value and produce an integer. In the case the JSON value was a numeric literal with a floating-point portion, JSONDecoder used different type-eraser methods during validation than it did during the final casting of the value. The checked casting produces a deterministic crash due to this mismatch. The JSONDecoder class is often wrapped by popular Swift-based web frameworks to parse the body of HTTP requests and perform basic type validation. This makes the attack low-effort: sending a specifically crafted JSON document during a request to these endpoints will cause them to crash. The attack does not have any confidentiality or integrity risks in and of itself; the crash is produced deterministically by an abort function that ensures that execution does not continue in the face of this violation of assumptions. However, unexpected crashes can lead to violations of invariants in services, so it's possible that this attack can be used to trigger error conditions that escalate the risk. Producing a denial of service may also be the goal of an attacker in itself. This issue is solved in Swift 5.6.2 for Linux and Windows. This issue was solved by ensuring that the same methods are invoked both when validating and during casting, so that no type mismatch occurs. Swift for Linux and Windows versions are not ABI-interchangeable. To upgrade a service, its owner must update to this version of the Swift toolchain, then recompile and redeploy their software. The new version of Swift includes an updated swift-corelibs-foundation package. Versions of Swift running on Darwin-based operating systems are not affected.

The weakness was disclosed 06/16/2022 as GHSA-239c-6cv2-wwx8. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2022-1642 since 05/09/2022. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 5.6.2 eliminates this vulnerability.

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Productinfo

Vendor

• Apple

Name

• Swift

Version

• 5.6.0
• 5.6.1

License

• commercial

Website

• Vendor: https://www.apple.com/

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