CVE-2024-27808: Apple Safari RCE Vulnerability

CVE-2024-27808 Overview

CVE-2024-27808 is a memory handling vulnerability affecting Apple's WebKit browser engine across multiple operating systems and Safari. Processing maliciously crafted web content can lead to arbitrary code execution on the targeted device. Apple addressed the issue with improved memory handling in Safari 17.5, iOS 17.5, iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, visionOS 1.2, and watchOS 10.5. The vulnerability is categorized under [CWE-786] (Access of Memory Location Before Start of Buffer) and carries a network-exploitable risk requiring user interaction such as visiting a crafted web page.

Critical Impact

An attacker who entices a user to load malicious web content can achieve arbitrary code execution within the context of the WebKit rendering process, potentially leading to full device compromise.

Affected Products

• Apple Safari (prior to 17.5)
• Apple iOS and iPadOS (prior to 17.5)
• Apple macOS Sonoma (prior to 14.5), tvOS (prior to 17.5), visionOS (prior to 1.2), and watchOS (prior to 10.5)

Discovery Timeline

• 2024-06-10 - CVE-2024-27808 published to the National Vulnerability Database (NVD)
• 2026-04-02 - Last updated in NVD database

Technical Details for CVE-2024-27808

Vulnerability Analysis

The flaw resides within Apple's WebKit browser engine, which powers Safari and renders web content across Apple's operating systems. When WebKit parses or processes specifically crafted web content, it mishandles memory access boundaries, leading to memory corruption. Apple states the issue was resolved through improved memory handling, indicating an out-of-bounds memory access condition consistent with [CWE-786].

Successful exploitation grants the attacker arbitrary code execution within the rendering process. From that foothold, attackers commonly chain additional sandbox escape or privilege escalation flaws to fully compromise the device. The vulnerability affects every Apple operating system that ships with WebKit, expanding the attack surface to phones, tablets, desktops, watches, TVs, and Vision Pro headsets.

Root Cause

The root cause is improper memory access handling within WebKit's content processing logic. The CWE-786 classification points to memory being accessed before the start of a valid buffer, a pattern typically caused by incorrect pointer arithmetic, missing bounds validation, or flawed assumptions about object layouts during JavaScript or DOM operations.

Attack Vector

Exploitation requires a victim to load attacker-controlled web content using a vulnerable WebKit version. The delivery method can include a phishing link, a compromised website, a malicious advertisement, or any application that embeds a WebView component. No authentication is required, and the exploit executes purely from web content parsing once the user opens the page.

No public proof-of-concept exploit code is referenced in the vendor or NVD data for this CVE. Refer to the Apple security advisories for technical context on the affected component and patch versions.

Detection Methods for CVE-2024-27808

Indicators of Compromise

• Unexpected child processes spawned by Safari, WebKit content processes, or applications hosting WKWebView components
• Outbound network connections from browser-related processes to unfamiliar domains immediately after web page visits
• Crash logs referencing WebKit, JavaScriptCore, or out-of-bounds memory access on affected Apple operating systems

Detection Strategies

• Inventory Apple endpoints running Safari, iOS, iPadOS, macOS, tvOS, visionOS, or watchOS builds older than the patched versions listed in Apple's advisories
• Correlate browser process telemetry with subsequent file writes, persistence attempts, or credential access activity
• Monitor mobile device management (MDM) compliance reports for devices that have not received the 17.5 / 14.5 / 1.2 / 10.5 update train

Monitoring Recommendations

• Enable behavioral monitoring on macOS endpoints to flag anomalous activity originating from Safari and WebKit-backed applications
• Track DNS and HTTP egress from browsers to identify visits to known malicious or newly registered domains hosting exploit content
• Review endpoint detection and response (EDR) telemetry for memory corruption indicators and unusual entitlements being requested by browser child processes

How to Mitigate CVE-2024-27808

Immediate Actions Required

• Update Safari to 17.5 and Apple operating systems to iOS/iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, visionOS 1.2, and watchOS 10.5
• Prioritize patching for users in high-risk roles such as executives, developers, and administrators who handle sensitive data
• Enforce update compliance through MDM policies and block enrollment of devices running unsupported OS versions

Patch Information

Apple released fixes through the security updates documented in the official advisories. Review the relevant Apple Support documents for build numbers and applicability: HT214101, HT214102, HT214103, HT214104, HT214106, and HT214108. Additional disclosure details are available on the Full Disclosure mailing list.

Workarounds

• Restrict browsing to trusted sites and deploy DNS filtering or secure web gateway controls to block known malicious domains until patches are applied
• Disable or limit JavaScript execution on untrusted sites via Safari content blockers or enterprise configuration profiles
• Apply Apple's Lockdown Mode on high-risk devices to reduce the WebKit attack surface

# Configuration example: verify installed versions on macOS
sw_vers -productVersion
defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

# Force MDM-managed software update on macOS
sudo softwareupdate -ia --restart