Cyber Resilience

CVE-2024-8381

Memory Safety in Mozilla Firefox Esr ≤ 115.15

Published
03 September 2024
Modified
04 November 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.044 90th percentile
Risk Priority 81 floored blend · peak EPSS

Summary

CVE-2024-8381 is a critical-severity Type Confusion (CWE-843) vulnerability in Mozilla Firefox Esr. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 10% of CVEs by exploit likelihood; 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 SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2024-8381 is a type confusion vulnerability (CWE-843) that can be triggered when performing a property name lookup on an object used as the `with` environment in the JavaScript engine. It affects Firefox versions prior to 130, Firefox ESR versions prior to 128.2 and 115.15, and Thunderbird versions prior to 128.2 and 115.15.

An unauthenticated remote attacker can exploit the flaw over the network by serving malicious web content or email that causes the browser or client to perform the unsafe lookup, resulting in arbitrary code execution with full impact to confidentiality, integrity, and availability.

Mozilla security advisories MFSA2024-39, MFSA2024-40, MFSA2024-41, and MFSA2024-43, along with the associated Bugzilla entry, direct users to upgrade to the fixed releases to eliminate the issue.

The EPSS score has remained in the 0.11–0.12 range with only a modest peak, indicating moderate but not rapidly escalating exploitation interest.

EU & UK References

Vulnerability Data

A potentially exploitable type confusion could be triggered when looking up a property name on an object being used as the `with` environment. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2,…

more

and Thunderbird < 115.15.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-8385Same product: Mozilla Firefox
CVE-2026-4702Same product: Mozilla Firefox
CVE-2023-4057Same product: Mozilla Firefox
CVE-2024-8384Same product: Mozilla Firefox
CVE-2023-25744Same product: Mozilla Firefox
CVE-2026-16355Same product: Mozilla Firefox
CVE-2025-14325Same product: Mozilla Firefox
CVE-2023-28162Same product: Mozilla Firefox
CVE-2026-16410Same product: Mozilla Firefox
CVE-2026-2796Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 130.0
mozilla
firefox esr
≤ 115.15 · 128.0 — 128.2

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

Mitigating Controls (NIST 800-53 r5) AI

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

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.

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.

References