CVE-2025-31215: Apple Safari DOS Vulnerability

CVE-2025-31215 Overview

CVE-2025-31215 is an improper input validation vulnerability affecting Apple's WebKit browser engine across multiple Apple platforms including Safari, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. The vulnerability allows remote attackers to cause an unexpected process crash by processing maliciously crafted web content, resulting in a denial of service condition.

Critical Impact

Processing maliciously crafted web content may lead to an unexpected process crash, disrupting user browsing sessions and potentially affecting system stability across Apple devices.

Affected Products

• Apple Safari prior to version 18.5
• Apple iOS 18.5 and iPadOS 18.5 (and iPadOS 17.7.7)
• Apple macOS Sequoia prior to version 15.5
• Apple tvOS prior to version 18.5
• Apple visionOS prior to version 2.5
• Apple watchOS prior to version 11.5

Discovery Timeline

• May 12, 2025 - CVE-2025-31215 published to NVD
• November 3, 2025 - Last updated in NVD database

Technical Details for CVE-2025-31215

Vulnerability Analysis

This vulnerability is classified as CWE-20 (Improper Input Validation), which occurs when software does not properly validate input from an external source. In the context of WebKit, the browser engine fails to adequately validate certain properties or attributes within web content before processing. When a user visits a malicious webpage or loads compromised web content, the inadequate input validation triggers an unhandled exception or error condition that causes the browser process to terminate unexpectedly.

The vulnerability requires user interaction—specifically, a user must be tricked into visiting a malicious website or loading attacker-controlled web content. While the impact is limited to availability (denial of service) rather than confidentiality or integrity compromise, repeated exploitation could significantly disrupt productivity on affected Apple devices.

Root Cause

The root cause of CVE-2025-31215 lies in insufficient input validation checks within WebKit's content processing logic. When parsing or rendering specific web content structures, the engine encounters malformed or unexpected data that was not properly sanitized or bounds-checked, leading to a crash condition. Apple addressed this by implementing "improved checks" to properly validate input before processing.

Attack Vector

The attack vector for this vulnerability is network-based, requiring user interaction. An attacker must host or inject malicious web content and convince the victim to load it through any of the affected Apple browsers or embedded WebKit components. Attack scenarios include:

• Hosting malicious content on an attacker-controlled website
• Injecting malicious content via compromised advertisements (malvertising)
• Exploiting web applications that embed user-supplied content
• Distributing malicious links via email or messaging platforms

The vulnerability does not require any privileges on the target system, and the impact is localized to the user's browsing session, causing immediate process termination when the malicious content is processed.

Detection Methods for CVE-2025-31215

Indicators of Compromise

• Repeated unexpected Safari or WebKit-based browser crashes when visiting specific websites
• Crash logs indicating WebKit process termination with input validation or parsing-related errors
• User reports of browser instability correlated with specific web content access
• System logs showing multiple com.apple.WebKit process crashes in short succession

Detection Strategies

• Monitor system crash reports for WebKit-related process terminations across managed Apple devices
• Implement network traffic analysis to identify known malicious domains serving exploit content
• Deploy endpoint detection solutions capable of correlating browser crashes with recently accessed URLs
• Review proxy logs for suspicious web content patterns that precede reported browser crashes

Monitoring Recommendations

• Enable crash reporting collection on managed iOS, macOS, and other Apple devices to identify exploitation attempts
• Monitor for anomalous patterns of browser process restarts that may indicate active exploitation
• Track security advisory feeds for updates on active exploitation campaigns targeting this vulnerability
• Configure SentinelOne agents to detect and alert on repeated WebKit process crashes as potential exploitation indicators

How to Mitigate CVE-2025-31215

Immediate Actions Required

• Update all Apple devices to the patched versions: watchOS 11.5, tvOS 18.5, iPadOS 17.7.7, iOS 18.5 and iPadOS 18.5, macOS Sequoia 15.5, visionOS 2.5, and Safari 18.5
• Prioritize updates on devices used for high-risk browsing activities or in enterprise environments
• Advise users to avoid clicking suspicious links or visiting untrusted websites until patches are applied
• Consider temporarily restricting web browsing on critical systems if immediate patching is not feasible

Patch Information

Apple has released security updates addressing this vulnerability across all affected platforms. Detailed patch information is available in the following Apple Security Advisories:

• Apple Support Document #122404
• Apple Support Document #122405
• Apple Support Document #122716
• Apple Support Document #122719
• Apple Support Document #122720
• Apple Support Document #122721
• Apple Support Document #122722

Linux distributions using WebKitGTK should also apply relevant patches, as noted in the Debian LTS Announcement.

Workarounds

• Enable content blockers in Safari to reduce exposure to potentially malicious web content
• Configure managed browsers to block access to known malicious or untrusted domains
• Use web filtering solutions to restrict access to high-risk website categories
• Disable JavaScript in Safari preferences for non-essential browsing (note: this may break legitimate website functionality)
• Consider using alternative browsers temporarily on systems where immediate patching is not possible

# Check current Safari version on macOS
/Applications/Safari.app/Contents/MacOS/Safari --version

# Check current macOS version
sw_vers -productVersion

# Force software update check on macOS
softwareupdate --list

# Install available updates on macOS
sudo softwareupdate --install --all