Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities

Overview

Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.6.3, deserializeTypedArray in fromJSON and fromCrossJSON trusts a deserialized source value as an ArrayBuffer and does not bound the serialized element count. An attacker can provide a small untrusted JSON object with a large length value, causing the array-like TypedArray constructor to synchronously allocate the selected number of elements and exhaust CPU or memory while starving the event loop. The offset check does not reject the crafted source because source.byteLength is undefined. DataView reaches a similar unchecked cast but throws rather than allocating, and the issue has no identified confidentiality or integrity impact. This issue is fixed in version 1.6.3.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.