Cyber Posture

CVE-2025-1011

HighRCE

Published: 04 February 2025

Published
04 February 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0021 43.8th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-1011 is a high-severity Code Injection (CWE-94) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 43.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SC-18 (Mobile Code).

Threat & Defense at a Glance

What attackers do: exploitation maps to Drive-by Compromise (T1189) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly requires timely patching of the WebAssembly code generation flaw in vulnerable Firefox and Thunderbird versions to eliminate the code execution risk.

prevent

Ensures organizations receive and act on security advisories like Mozilla MFSA 2025-07, enabling prompt remediation of CVE-2025-1011.

SC-18 Mobile Code partial match
prevent

Controls execution and scanning of mobile code such as WebAssembly to mitigate exploitation of code generation bugs leading to crashes and code injection.

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Direct RCE via malicious site visit (drive-by) or crafted file enables client-side exploitation.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A bug in WebAssembly code generation could have lead to a crash. It may have been possible for an attacker to leverage this to achieve code execution. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and…

more

Thunderbird 135.

Deeper analysisAI

CVE-2025-1011 is a vulnerability in the WebAssembly code generation component of Mozilla Firefox and Thunderbird products. The issue manifests as a bug that could cause a crash and potentially be leveraged by an attacker to achieve arbitrary code execution. It affects versions of Firefox prior to 135, Firefox ESR prior to 128.7, Thunderbird prior to 128.7, and Thunderbird prior to 135, with a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and association to CWE-94 (Code Injection).

An attacker can exploit this vulnerability remotely over the network with low complexity and no required privileges, though it necessitates user interaction, such as visiting a malicious site or opening a crafted file. Successful exploitation could result in high-impact confidentiality, integrity, and availability violations, including the potential for code execution within the browser's sandboxed environment.

Mozilla addressed the vulnerability in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135, as detailed in security advisories MFSA 2025-07, MFSA 2025-09, MFSA 2025-10, and MFSA 2025-11, along with Bugzilla entry 1936454. Security practitioners should prioritize updating affected products to these patched versions to mitigate the risk.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 128.7.0 · ≤ 135.0
mozilla
thunderbird
≤ 135.0 · 128.0.1 — 128.7.0

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References