External risk intelligence

Apple Web Content Processing Vulnerability Allows Unexpected Process Crash

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-43342

The vulnerability affects web browsers (Safari, WebKitGTK, WPE WebKit) and OS components that process web content. Since these products are specifically designed to ingest, render, and interact with arbitrary, potentially malicious content from the public internet as their primary function, they are commonly exposed to internet-sourced threats during routine user activity.

Apple Safari

before 26.0before 18.7before 2.48.7

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory addresses a correctness issue within Apple's Safari and other related products, including iOS and macOS. The vulnerability, if exploited by maliciously crafted web content, could lead to an unexpected process crash, which is a critical security concern due to its potential for broad impact.

Malicious web content could crash applications.
Critical issue affects widely used Apple software.
Confirm relevance and assess exposure to this risk.

Attack Path

How an attacker could exploit the issue

An attacker can target users by sending them specially crafted web content. If a user views this malicious content, it could cause an application to crash unexpectedly.

No specific entry conditions are identified.
Viewing malicious web content triggers the vulnerability.
Risk includes unexpected application crashes.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, processing maliciously crafted web content could lead to an unexpected process crash. This type of issue may affect the stability and availability of the affected service or application.

Browser stability.
Unexpected process crash.
Service or application disruption.

Operational Fix

Recommended remediation, mitigation, and detection steps

This critical vulnerability impacts Apple's Safari browser and related operating systems, as well as WebKitGTK and WPE WebKit. Ownership likely resides with application owners for Safari, platform teams for the OS components, and potentially vendor-management for WebKit-based products. The first practical step is to identify all instances of these affected technologies, determine their internet reachability and business criticality, and then assign an owner to plan remediation based on risk.

Assign ownership to relevant application/platform teams.
Verify internet-reachable, business-critical instances.
Plan remediation during scheduled maintenance windows.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Free EASM Trial See How Signal Works

Frequently asked questions

What is Safari and the WebKit-based software mentioned in CVE-2025-43342?

Safari is Apple's web browser, while WebKitGTK and WPE WebKit are open-source browser engines used by various Linux and embedded applications. These tools are responsible for interpreting HTML, CSS, and JavaScript to render the websites you visit. Because they handle complex code from the internet, they are foundational components for displaying web content across Apple operating systems and numerous cross-platform applications.

What does this vulnerability mean in plain English?

This vulnerability is classified as improper input validation (CWE-20). It means the software does not correctly check or sanitize the data it receives from web pages. Because these checks are flawed, the application becomes confused when processing specifically prepared, malicious content, which ultimately forces the software to crash and stop working.

How is this vulnerability triggered?

The flaw is triggered when a user visits a website or interacts with web content that has been specifically crafted to exploit this weakness. Simply having the software installed is not enough to cause a crash; the application must actively load and process the malicious data for the instability to occur.

Is my system at risk according to Halo Surface Signal?

Yes, if you use these products. Halo Surface Signal identifies these components as highly exposed because their primary purpose is to interact with arbitrary content from the public internet. Since these browsers and engines are designed to fetch data from external sources, they frequently encounter the types of malicious content capable of triggering this crash.

What is the first step to address CVE-2025-43342?

Start by auditing your environment to locate all systems running affected versions of Safari, iOS, macOS, or WebKit-based software. Once you have an inventory, prioritize updating the most critical or internet-facing systems. Plan the installation of the vendor-provided patches during your next standard maintenance window to restore system stability and safety.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.