CVE-2021-44992 in Jerryscript
Summary
by MITRE • 01/25/2022
There is an Assertion ''ecma_object_is_typedarray (obj_p)'' failed at /jerry-core/ecma/operations/ecma-typedarray-object.c in Jerryscript 3.0.0.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/28/2022
The vulnerability identified as CVE-2021-44992 represents a critical assertion failure within the JerryScript JavaScript engine version 3.0.0, specifically occurring in the ecma_typedarray_object.c source file. This assertion failure manifests as a condition check that evaluates to false, causing the engine to terminate execution abruptly when processing certain typed array objects. The assertion ecma_object_is_typedarray(obj_p) serves as a safety mechanism to validate that an object is indeed a typed array before proceeding with subsequent operations, yet this validation mechanism itself becomes a point of failure when the underlying object structure does not meet expected criteria.
The technical flaw stems from insufficient input validation and object type checking within the JavaScript engine's typed array implementation. When the JerryScript engine encounters malformed or improperly constructed typed array objects during execution, the assertion fails because the object does not conform to the expected typed array structure despite appearing to be one. This condition creates a potential denial of service scenario where legitimate script execution can be interrupted by maliciously crafted JavaScript code designed to trigger this specific assertion failure. The vulnerability is particularly concerning because it occurs at the core operations level of the engine, where type validation should be robust and reliable.
Operationally, this vulnerability presents significant risks to systems relying on JerryScript for embedded JavaScript execution, particularly in IoT devices, embedded systems, and mobile applications where the engine is used to process untrusted input. An attacker could potentially exploit this assertion failure to cause application crashes or system instability, effectively creating a denial of service condition that disrupts normal operations. The impact extends beyond simple service interruption as the assertion failure could potentially be leveraged in more sophisticated attacks where the engine's termination might be used as a stepping stone for further exploitation, especially in environments where the JavaScript engine is part of a larger security-critical system.
Mitigation strategies should focus on immediate patching of the JerryScript engine to version 3.0.1 or later, which contains the necessary fixes to properly validate typed array objects before assertion checks. Organizations should also implement input sanitization measures at the application level to prevent malformed JavaScript from reaching the engine, including comprehensive validation of all typed array operations and proper error handling for type checking failures. Additionally, system administrators should consider implementing runtime monitoring to detect unusual termination patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-254 and CWE-611 categories, representing weaknesses in security features and improper access control, while potentially mapping to ATT&CK techniques involving denial of service and privilege escalation through software exploitation.