Product:
QuickJS
Summary
A vulnerability exists in the QuickJS engine’s BigInt string parsing logic when creating a BigInt from a string with an excessively large number of digits. The function’s calculation for the necessary bits can exceed the maximum value of a standard signed 32-bit integer, leading to an Integer Overflow. This results in an underestimated memory allocation for the BigInt object, causing a Heap Out-of-Bounds Write when data is written past the allocated buffer.
Details
| Severity | Base Score | CVE |
|---|---|---|
| HIGH | 7.1 | CVE-2025-62496 |
Exploitation
To exploit this vulnerability, an attacker can provide a string input with an excessively large number of digits when creating a BigInt. This input will cause the internal calculations to overflow, leading to incorrect memory allocation. When the function attempts to write the BigInt data into the allocated memory, it will exceed the buffer size, allowing the attacker to manipulate memory and potentially execute arbitrary code.
Affected Products
- QuickJS: Vulnerable due to flawed BigInt string parsing logic that can lead to memory corruption.
Mitigation
To mitigate this vulnerability, it is recommended to validate input strings for BigInt creation to ensure they do not exceed a safe length. Additionally, updating to the latest version of QuickJS that addresses this issue will help prevent exploitation.