CVE-2025-43214: Apple Safari DOS Vulnerability

CVE-2025-43214 Overview

CVE-2025-43214 is a memory handling vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can cause an unexpected Safari crash, resulting in a denial-of-service condition. Apple addressed the issue with improved memory handling across Safari 18.6, iOS 18.6, iPadOS 18.6, macOS Sequoia 15.6, tvOS 18.6, visionOS 2.6, and watchOS 11.6. The vulnerability requires user interaction, as a target user must visit or render malicious web content served by an attacker. The weakness maps to memory buffer errors classified under [CWE-119] and [CWE-120].

Critical Impact
Remote attackers can crash Safari on unpatched Apple devices by luring users to malicious web content, disrupting browsing sessions and availability of the browser process.

Affected Products

Apple Safari (versions prior to 18.6)
Apple iOS and iPadOS (versions prior to 18.6), Apple macOS Sequoia (versions prior to 15.6)
Apple tvOS 18.6, visionOS 2.6, and watchOS 11.6 (prior versions)

Discovery Timeline

2025-07-30 - CVE-2025-43214 published to the National Vulnerability Database (NVD)
2026-06-30 - Last updated in NVD database

Technical Details for CVE-2025-43214

Vulnerability Analysis

The vulnerability resides in Safari's handling of web content, where malformed or maliciously structured input triggers improper memory operations. When Safari processes the crafted content, the browser fails to enforce correct buffer boundaries, resulting in memory corruption that terminates the browser process. The flaw is exploitable over the network with low attack complexity and does not require authentication, though it does require user interaction to load the malicious page. Apple's advisory attributes the fix to improved memory handling, which typically indicates stricter buffer bounds enforcement and safer allocation patterns within WebKit or related components.

Root Cause

The root cause is a memory buffer error within Safari's web content processing pipeline, corresponding to [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer) and [CWE-120] (Buffer Copy without Checking Size of Input). Insufficient validation of input sizes or offsets during content parsing allows out-of-bounds memory operations. These conditions destabilize the browser process rather than yielding code execution, based on the CVSS impact profile (availability-only).

Attack Vector

An attacker hosts crafted web content on a controlled website or delivers it through a compromised third-party page, advertisement, or iframe. When a user browsing with a vulnerable version of Safari or another affected Apple OS component loads the content, the memory handling flaw triggers and the browser crashes. Repeated navigation to the malicious content produces a sustained denial-of-service condition against the browser. No verified public exploit or proof-of-concept has been published, and the CVE is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified exploit code is available for CVE-2025-43214. See the Apple Support Document #124147 and related advisories for vendor-provided technical context.

Detection Methods for CVE-2025-43214

Indicators of Compromise

Unexpected Safari or WebKit-based application crashes correlated with visits to untrusted URLs
Crash logs on macOS, iOS, or iPadOS referencing com.apple.WebKit or Safari processes terminating with memory-related signals
Repeated crash reports from multiple endpoints navigating to the same external domain

Detection Strategies

Monitor endpoint telemetry for abnormal termination of Safari.app and WebKit helper processes across managed Apple devices
Correlate browser crash events with outbound network requests to newly observed or low-reputation domains
Review MDM-collected diagnostic logs and ReportCrash output for signatures consistent with memory corruption in web content rendering

Monitoring Recommendations

Track Safari and Apple OS version inventory to identify endpoints running builds below Safari 18.6, iOS 18.6, iPadOS 18.6, macOS 15.6, tvOS 18.6, visionOS 2.6, and watchOS 11.6
Alert on clusters of browser crashes affecting multiple users within short time windows
Ingest web proxy and DNS logs into a central analytics platform to trace users to the origin of suspected malicious pages

How to Mitigate CVE-2025-43214

Immediate Actions Required

Update all Apple devices to the fixed versions: Safari 18.6, iOS 18.6, iPadOS 18.6, macOS Sequoia 15.6, tvOS 18.6, visionOS 2.6, and watchOS 11.6
Enforce updates through Mobile Device Management (MDM) policies for managed fleets
Communicate advisory guidance to end users, especially those handling sensitive workflows in Safari

Patch Information

Apple released fixes across multiple platforms. Refer to the following vendor advisories: Apple Support Document #124147, Apple Support Document #124149, Apple Support Document #124152, Apple Support Document #124153, Apple Support Document #124154, and Apple Support Document #124155. Red Hat has also published downstream advisories tracked under the Red Hat CVE Detail for CVE-2025-43214.

Workarounds

Avoid visiting untrusted or unknown websites using vulnerable versions of Safari until patches are applied
Use an alternative, up-to-date browser on affected macOS systems where feasible until updates can be deployed
Restrict access to unclassified web content via enterprise web filtering or DNS-based blocking of known malicious domains

bash

# Verify Safari version on macOS
defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

# Check macOS version to confirm patch level
sw_vers -productVersion

# Trigger a software update check via CLI
sudo softwareupdate --list
sudo softwareupdate --install --all --restart