CVE-2025-24182 Overview
CVE-2025-24182 is an out-of-bounds read vulnerability [CWE-125] affecting font processing across Apple's operating system portfolio. Apple addressed the flaw through improved input validation in iOS 18.4, iPadOS 18.4, macOS Sequoia 15.4, tvOS 18.4, visionOS 2.4, and watchOS 11.4. Processing a maliciously crafted font can result in the disclosure of process memory to an attacker.
Exploitation requires local access and user interaction, such as opening a document or rendering a font-embedded file. The impact is limited to information disclosure, with no direct integrity or availability consequences.
Critical Impact
A maliciously crafted font can leak process memory across iOS, iPadOS, macOS, tvOS, visionOS, and watchOS, potentially exposing sensitive data used in address space layout randomization (ASLR) bypasses.
Affected Products
- Apple iOS and iPadOS (prior to 18.4)
- Apple macOS Sequoia (prior to 15.4)
- Apple visionOS (prior to 2.4), tvOS (prior to 18.4), and watchOS (prior to 11.4)
Discovery Timeline
- 2025-03-31 - CVE-2025-24182 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-24182
Vulnerability Analysis
The vulnerability resides in Apple's font parsing subsystem, which is shared across the CoreText and font-handling components of iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. When the parser processes a specially crafted font file, it reads beyond the allocated bounds of a memory buffer. The out-of-bounds read returns adjacent heap or stack memory, which the parser then incorporates into its processing pipeline.
An attacker who controls the crafted font can influence which memory regions are touched during parsing. The disclosed bytes may contain heap metadata, pointers, stack canaries, or sensitive application data. Attackers commonly chain such disclosures with memory corruption bugs to defeat ASLR before achieving code execution.
Root Cause
The root cause is missing input validation on length or offset fields inside the font file structure. The parser trusted attacker-supplied metadata when computing read offsets, allowing reads past buffer boundaries. Apple's advisories describe the fix as "improved input validation," indicating added bounds checks before dereferencing font table data.
Attack Vector
Exploitation requires an attacker to deliver a crafted font to the target system. Delivery vectors include documents embedding the font, web pages referencing it, email attachments, or messages containing font-embedded content. The target must open or preview the content, satisfying the user interaction requirement.
Because font parsing runs in multiple system processes, including client-side rendering services, the leaked memory may originate from privileged processes. See the Apple Support advisory for platform-specific details.
Detection Methods for CVE-2025-24182
Indicators of Compromise
- Unexpected crashes or abnormal termination of font-rendering processes such as fontd or CoreText clients.
- Delivery of documents, PDFs, or web content containing embedded fonts from untrusted sources.
- Anomalous memory access patterns or diagnostic reports referencing font parsing modules.
Detection Strategies
- Monitor endpoint telemetry for repeated crashes in font-handling processes across Apple devices.
- Inspect email and web gateways for attachments carrying embedded or standalone font files (.ttf, .otf, .woff, .woff2) from untrusted origins.
- Correlate diagnostic reports uploaded to MDM platforms with recent user activity involving unfamiliar documents.
Monitoring Recommendations
- Ingest Apple Unified Log data and endpoint diagnostics into a centralized analytics platform for retrospective queries.
- Track OS version compliance across the managed Apple fleet and flag devices still running versions earlier than iOS 18.4, macOS 15.4, tvOS 18.4, visionOS 2.4, or watchOS 11.4.
- Alert on outbound data transfers that immediately follow font-rendering process anomalies.
How to Mitigate CVE-2025-24182
Immediate Actions Required
- Update all Apple devices to the fixed versions: iOS 18.4, iPadOS 18.4, macOS Sequoia 15.4, tvOS 18.4, visionOS 2.4, and watchOS 11.4.
- Enforce update compliance through Mobile Device Management (MDM) policies and block enrollment for devices on outdated builds.
- Instruct users to avoid opening documents or fonts from untrusted senders until patches are deployed.
Patch Information
Apple published fixes in the March 2025 security release cycle. Refer to the vendor advisories for exact build numbers: Apple Support #122371, Apple Support #122373, Apple Support #122377, and Apple Support #122378.
Workarounds
- Restrict installation of untrusted fonts and disable automatic preview of font-embedded documents where feasible.
- Use email and web filtering to strip or quarantine font attachments from unknown senders.
- Apply application sandboxing and least-privilege configurations to limit the value of any leaked memory.
# Verify current OS build on macOS to confirm the patch is applied
sw_vers
# Expected ProductVersion: 15.4 or later
# Check iOS/iPadOS build via MDM query or Settings > General > About > Software Version
# Expected: 18.4 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
