CVE-2025-31204: Apple Safari Buffer Overflow Vulnerability

CVE-2025-31204 Overview

CVE-2025-31204 is a memory corruption vulnerability affecting Apple's WebKit browser engine across multiple Apple platforms. The vulnerability exists due to improper memory handling when processing web content. An attacker can exploit this flaw by crafting malicious web content that, when processed by an affected browser or application, triggers memory corruption that could lead to arbitrary code execution or system compromise.

This vulnerability impacts a wide range of Apple devices and platforms, including Safari browser, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. The network-based attack vector combined with the potential for full system compromise makes this a significant security concern for Apple ecosystem users.

Critical Impact

Processing maliciously crafted web content may lead to memory corruption, potentially enabling attackers to execute arbitrary code, compromise user data confidentiality and integrity, or cause application crashes across Apple devices.

Affected Products

• Apple Safari versions prior to 18.5
• Apple iOS and iPadOS versions prior to 18.5
• Apple macOS Sequoia versions prior to 15.5
• Apple tvOS versions prior to 18.5
• Apple visionOS versions prior to 2.5
• Apple watchOS versions prior to 11.5

Discovery Timeline

• May 12, 2025 - CVE-2025-31204 published to NVD
• November 03, 2025 - Last updated in NVD database

Technical Details for CVE-2025-31204

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), indicating a memory boundary violation issue within WebKit's content processing routines. The flaw allows operations to occur outside the intended memory buffer boundaries when handling specially crafted web content.

The vulnerability can be exploited remotely over a network connection and requires user interaction—typically visiting a malicious website or viewing malicious web content. Successful exploitation could result in complete compromise of confidentiality, integrity, and availability of the affected system, allowing attackers to execute code with the privileges of the current user.

Root Cause

The root cause of CVE-2025-31204 lies in improper memory handling within WebKit's content processing engine. When parsing or rendering certain types of maliciously crafted web content, the affected code fails to properly validate memory boundaries, leading to out-of-bounds memory operations. Apple addressed this issue by implementing improved memory handling routines that properly validate buffer boundaries during content processing.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the victim to interact with malicious web content. An attacker could exploit this vulnerability through several methods:

1. Malicious Website: Hosting crafted content on a website and luring victims to visit
2. Malvertising: Injecting malicious content through compromised advertising networks
3. Watering Hole Attacks: Compromising legitimate websites frequented by target victims
4. Phishing Campaigns: Sending links to malicious content via email or messaging platforms

The vulnerability requires user interaction (such as clicking a link or visiting a webpage) but does not require any special privileges, making it accessible to opportunistic attackers targeting a broad user base.

Detection Methods for CVE-2025-31204

Indicators of Compromise

• Unexpected Safari, WebKit, or WebContent process crashes or restarts
• Unusual memory consumption spikes in browser processes during web browsing
• Abnormal network connections originating from browser processes to unknown destinations
• System logs showing WebKit-related crash reports or memory access violations

Detection Strategies

• Monitor system crash reports for WebKit or Safari process crashes with memory corruption signatures
• Implement network traffic analysis to detect connections to known malicious domains or suspicious content delivery
• Deploy endpoint detection solutions capable of identifying memory corruption exploitation attempts
• Review Apple Security Updates compliance across managed devices to ensure patching status

Monitoring Recommendations

• Enable enhanced logging for Safari and WebKit processes on managed devices
• Configure crash report collection and analysis for early detection of exploitation attempts
• Implement web filtering to block access to known malicious domains serving exploit content
• Monitor for Apple Security Advisory notifications and ensure rapid patch deployment

How to Mitigate CVE-2025-31204

Immediate Actions Required

• Update all Apple devices to the latest patched versions immediately: Safari 18.5, iOS/iPadOS 18.5, macOS Sequoia 15.5, tvOS 18.5, visionOS 2.5, and watchOS 11.5
• Enable automatic software updates on all Apple devices to receive security patches promptly
• Educate users about the risks of visiting untrusted websites or clicking on suspicious links
• Consider implementing web filtering solutions to block access to potentially malicious content

Patch Information

Apple has released security updates addressing this vulnerability across all affected platforms. Organizations and users should apply these updates as soon as possible:

• Apple Support Advisory #122404 - Safari 18.5 security update
• Apple Support Advisory #122716 - iOS and iPadOS 18.5 security update
• Apple Support Advisory #122719 - macOS Sequoia 15.5 security update
• Apple Support Advisory #122720 - tvOS 18.5 security update
• Apple Support Advisory #122721 - visionOS 2.5 security update
• Apple Support Advisory #122722 - watchOS 11.5 security update

Additionally, Debian has released updates for affected WebKitGTK packages as noted in the Debian LTS Announcement June 2025.

Workarounds

• Use alternative browsers temporarily while awaiting patch deployment (note: this may not protect against all WebKit-based content rendering)
• Implement strict web content filtering to block potentially malicious JavaScript or HTML content
• Disable JavaScript in Safari settings as a temporary measure (may impact website functionality)
• Restrict browsing to known trusted websites until patches can be applied

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

# Check current macOS version
sw_vers -productVersion

# Trigger software update check on macOS
softwareupdate -l

# Install all available updates on macOS
softwareupdate -ia