CVE-2024-44240: Apple iPadOS Font Processing Vulnerability

CVE-2024-44240 Overview

CVE-2024-44240 is a memory disclosure vulnerability affecting Apple's font processing across its operating system portfolio. Processing a maliciously crafted font can result in the disclosure of process memory. Apple addressed the flaw with improved checks in iOS 17.7.1 and iPadOS 17.7.1, iOS 18.1 and iPadOS 18.1, macOS Sequoia 15.1, macOS Sonoma 14.7.1, macOS Ventura 13.7.1, tvOS 18.1, visionOS 2.1, and watchOS 11.1. The vulnerability requires local access and user interaction to trigger. While not remotely exploitable, memory disclosure primitives are frequently chained with other flaws to defeat address space layout randomization (ASLR) and enable more impactful exploitation.

Critical Impact
A maliciously crafted font file can leak sensitive process memory, potentially exposing cryptographic material, tokens, or pointer values usable in exploit chains.

Affected Products

Apple iOS and iPadOS prior to 17.7.1 and 18.1
Apple macOS Ventura 13.7.1, Sonoma 14.7.1, and Sequoia 15.1
Apple tvOS 18.1, visionOS 2.1, and watchOS 11.1

Discovery Timeline

2024-10-28 - CVE-2024-44240 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-44240

Vulnerability Analysis

The vulnerability resides in Apple's font parsing subsystem, which is shared across iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. Font formats such as TrueType and OpenType contain complex table structures with length fields, offsets, and index arrays. When these fields are not fully validated, the parser can read beyond intended buffer boundaries and return the resulting bytes to the calling process or render pipeline. According to Apple's advisories, the fix was implemented through improved checks, which is consistent with tightening bounds validation on untrusted font data. The vulnerability is classified as an information disclosure issue [NVD-CWE-noinfo] with confidentiality impact but no integrity or availability effect.

Root Cause

The root cause is insufficient validation of attacker-controlled fields inside a font file. A crafted font can direct the parser to read from memory locations adjacent to legitimate font data structures, exposing uninitialized or out-of-bounds process memory to the rendering context. Apple has not published low-level technical details, and no CWE has been assigned beyond the placeholder classification.

Attack Vector

Exploitation requires a local attack vector and user interaction. A victim must open a document, application, or webpage that causes the vulnerable operating system component to process the malicious font. Successful exploitation reveals process memory contents to the attacker-controlled rendering context. The disclosed data can include pointer values useful for bypassing ASLR, secrets held in memory, or fragments of other application data. No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified public exploit code exists for this vulnerability. Refer to the Apple Support advisories for vendor guidance and to the Full Disclosure archive entries listed in the references for community discussion.

Detection Methods for CVE-2024-44240

Indicators of Compromise

Font files (.ttf, .otf, .woff, .woff2) delivered via email, messaging, or web download from untrusted sources
Application crashes or unexpected termination in processes that handle font rendering, such as fontd or WebKit-based renderers
Unusual outbound traffic from font-consuming applications shortly after opening third-party documents or webpages

Detection Strategies

Monitor endpoint telemetry for Apple devices running operating system versions below the patched builds and prioritize them for update.
Inspect email and web gateways for attachments containing embedded or standalone font resources originating from untrusted senders.
Correlate crash reports from Apple diagnostic subsystems that reference font parsing libraries with subsequent process anomalies.

Monitoring Recommendations

Track operating system version compliance across managed Apple fleets through your mobile device management (MDM) platform.
Alert on installations of unsigned or unusual font files outside standard system font directories.
Baseline network activity from browsers and document readers to detect data staging following font-based exploitation attempts.

How to Mitigate CVE-2024-44240

Immediate Actions Required

Update all Apple devices to the patched releases: iOS/iPadOS 17.7.1 or 18.1, macOS Ventura 13.7.1, Sonoma 14.7.1, or Sequoia 15.1, tvOS 18.1, visionOS 2.1, and watchOS 11.1.
Enforce automatic updates through MDM policies for managed endpoints and mobile devices.
Advise users to avoid opening untrusted documents, webpages, or messages containing embedded fonts until patches are deployed.

Patch Information

Apple released fixes across its operating system portfolio in October 2024. Patch details are documented in the vendor advisories: Apple Support Article 121563, Apple Support Article 121565, Apple Support Article 121566, Apple Support Article 121567, Apple Support Article 121568, Apple Support Article 121569, and Apple Support Article 121570.

Workarounds

No official vendor workaround exists; patching is the required remediation path.
Restrict processing of fonts from unknown sources by blocking font file types at email and web gateways where feasible.
Reduce attack surface by disabling automatic font rendering in preview panes and disallowing installation of unmanaged fonts.

bash

# Verify current macOS version and prompt update via MDM or softwareupdate
sw_vers -productVersion
sudo softwareupdate --install --all --restart