CVE-2025-62492
Memory Safety in Quickjs Project Quickjs ≤ 2025-09-13
Raw vector
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2025-62492 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Quickjs Project Quickjs. Its CVSS base score is 5.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-34782
Vulnerability Data
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied. * The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position…
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for the search. * If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d: $$d_{new} = d + \text{len}$$ * Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$. * The result is then converted to an integer index $k$: $k = \text{len}$. * The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array. This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
Routine patching replaces vulnerable code containing out-of-bounds read flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.
Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.
Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.