CVE-2025-24189: Apple Safari Buffer Overflow Vulnerability

CVE-2025-24189 Overview

CVE-2025-24189 is a memory corruption vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can trigger memory corruption in the affected WebKit-based browser engine. Apple addressed the issue with improved checks in Safari 18.3, iOS 18.3, iPadOS 18.3, macOS Sequoia 15.3, tvOS 18.3, visionOS 2.3, and watchOS 11.3. The flaw is categorized under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer) and requires user interaction, typically by visiting an attacker-controlled web page.

Critical Impact
Successful exploitation can lead to memory corruption that may enable arbitrary code execution within the browser process when a user visits a malicious web page.

Affected Products

Apple Safari (versions prior to 18.3)
Apple iOS and iPadOS (versions prior to 18.3)
Apple macOS Sequoia (versions prior to 15.3), tvOS (prior to 18.3), visionOS (prior to 2.3), and watchOS (prior to 11.3)

Discovery Timeline

2025-05-19 - CVE-2025-24189 published to the National Vulnerability Database (NVD)
2026-04-02 - Last updated in the NVD database

Technical Details for CVE-2025-24189

Vulnerability Analysis

The vulnerability resides in the web content processing path used by Safari and the WebKit engine bundled with Apple operating systems. When the browser parses or renders maliciously crafted HTML, JavaScript, or related web content, internal memory operations cross intended buffer boundaries. The result is memory corruption that affects the confidentiality, integrity, and availability of the browser process.

Apple's advisory states the issue was resolved with improved checks, indicating that prior code paths lacked sufficient validation before performing memory operations on attacker-influenced data. The attack vector is network-based and requires user interaction, such as loading a crafted page. No authentication is required.

The Exploit Prediction Scoring System (EPSS) places the probability of observed exploitation activity at roughly the 76th percentile, indicating meaningful real-world risk despite no public proof-of-concept code being available at this time.

Root Cause

The root cause is improper restriction of operations within the bounds of a memory buffer [CWE-119] inside the web content processing component. Insufficient bounds or state checks allowed crafted input to influence memory access in an unsafe manner. Apple's fix introduces additional validation in the affected code paths.

Attack Vector

An attacker hosts or injects malicious web content on a page that a victim loads in Safari or a WebKit-based view on an affected Apple OS. Delivery channels include phishing links, compromised websites, malicious advertisements, and embedded WebKit views inside third-party iOS or macOS applications. No verified public exploit code is currently available.

// No verified proof-of-concept code is publicly available for CVE-2025-24189.
// Refer to Apple's security advisories listed in the references for technical context.

Detection Methods for CVE-2025-24189

Indicators of Compromise

Unexpected Safari or WebKit-hosting process crashes, particularly com.apple.WebKit.WebContent, following web browsing activity.
Crash reports referencing memory access violations in WebKit rendering or JavaScriptCore components.
Outbound network connections from browser or WebKit child processes to previously unseen domains immediately after a page load.

Detection Strategies

Inventory Apple endpoints to identify Safari, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS versions older than the fixed releases.
Correlate browser crash telemetry with URL history and DNS logs to identify pages that consistently trigger WebKit faults.
Monitor for child processes spawned by Safari or applications that embed WebKit, especially shell or scripting interpreters.

Monitoring Recommendations

Forward macOS unified logs and crash reports to a centralized logging platform for retention and analysis.
Track web proxy and DNS telemetry for connections to domains delivering exploit-like payloads or obfuscated JavaScript.
Alert on lateral movement or credential access activity originating from macOS hosts shortly after browser anomalies.

How to Mitigate CVE-2025-24189

Immediate Actions Required

Update all Apple devices to Safari 18.3, iOS 18.3, iPadOS 18.3, macOS Sequoia 15.3, tvOS 18.3, visionOS 2.3, or watchOS 11.3 or later.
Enforce update compliance through mobile device management (MDM) policies and block non-compliant devices from sensitive resources.
Educate users on avoiding untrusted links and unsolicited web content delivered through email or messaging applications.

Patch Information

Apple released fixes across its product family in the January 2025 security update cycle. Refer to the official advisories for each platform: Apple Support Document #122066, #122068, #122071, #122072, #122073, and #122074. Additional discussion is available on the OpenWall OSS Security List.

Workarounds

Restrict use of Safari and WebKit-based applications on unpatched devices until updates are deployed.
Deploy network filtering and URL reputation controls to block access to known malicious or unrated sites from Apple endpoints.
Enable Lockdown Mode on high-risk iOS and macOS devices to reduce the attack surface exposed to crafted web content.

bash

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

# Check macOS build version
sw_vers

# Trigger software update check via command line
sudo softwareupdate --list
sudo softwareupdate --install --all --restart