Cyber Resilience

CVE-2024-7520

RCE in Mozilla Firefox ≤ 129.0

Published
06 August 2024
Modified
24 March 2025
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0064 47th percentile
Risk Priority 65 floored blend · peak EPSS

Summary

CVE-2024-7520 is a high-severity Type Confusion (CWE-843) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 47th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A type confusion bug in WebAssembly could be leveraged by an attacker to potentially achieve code execution. This vulnerability affects Firefox < 129, Firefox ESR < 128.1, and Thunderbird < 128.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-1011Same product: Mozilla Firefox
CVE-2024-11699Same product: Mozilla Firefox
CVE-2026-8094Same product: Mozilla Firefox
CVE-2024-2610Same product: Mozilla Firefox
CVE-2025-8030Same product: Mozilla Firefox
CVE-2024-6602Same product: Mozilla Firefox
CVE-2025-14324Same product: Mozilla Firefox
CVE-2024-11697Same product: Mozilla Firefox
CVE-2023-28162Same product: Mozilla Firefox
CVE-2024-8381Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 129.0
mozilla
firefox esr
≤ 128.1.0
mozilla
thunderbird
≤ 128.1.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.5.2
  • V3.2.3
  • V15.3.5
  • V1.3.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including fuzzing and type-aware analysis) directly finds type-confusion flaws before deployment.

Input validation directly stops untrusted data from being used to construct executable code without neutralization.

Least privilege limits the damage an injected code fragment can perform once executed.

Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.

Engineering principles can require use of type-safe languages, static typing, and runtime type checks that structurally avoid allocating one type and accessing another.

Memory-protection controls limit the blast radius when a type-confusion access occurs but do not stop the flaw itself.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

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.

finds

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

prevents

Application security requirements can specify strong typing and interface contracts that reduce type confusion.

prevents

Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.

prevents

Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.

none

Controls that restrict unauthorized or malicious code from being introduced via external networks or removable media limit opportunities for an attacker to inject and execute arbitrary code.

References