CVE-2025-43338: Apple iPadOS Buffer Overflow Vulnerability

CVE-2025-43338 Overview

CVE-2025-43338 is an out-of-bounds access vulnerability affecting Apple iOS, iPadOS, and macOS. The flaw resides in media file processing components and triggers when the operating system parses a maliciously crafted media file. Successful exploitation leads to unexpected application termination or corruption of process memory.

Apple addressed the issue with improved bounds checking in iOS 26, iPadOS 26, macOS Sonoma 14.8.2, macOS Sonoma 14.8.4, and macOS Tahoe 26. The vulnerability requires local access and user interaction, such as opening a crafted file. Memory corruption outcomes can disrupt application availability and potentially serve as a primitive for further exploitation chains.

Critical Impact
Processing a maliciously crafted media file may corrupt process memory or terminate the host application, undermining confidentiality and availability on affected Apple devices.

Affected Products

Apple iOS (versions prior to iOS 26)
Apple iPadOS (versions prior to iPadOS 26)
Apple macOS (Sonoma prior to 14.8.2/14.8.4, Tahoe prior to 26)

Discovery Timeline

2025-11-04 - CVE-2025-43338 published to the National Vulnerability Database (NVD)
2026-04-02 - Last updated in NVD database

Technical Details for CVE-2025-43338

Vulnerability Analysis

The vulnerability is an out-of-bounds access defect [CWE-79 as listed in NVD, though the description aligns with out-of-bounds memory access semantics] within Apple's media file handling logic. When a target opens or previews a crafted media file, the parser reads or writes memory beyond an allocated buffer. This behavior corrupts adjacent process memory or triggers an access violation that terminates the host application.

Apple's advisories indicate the root cause was addressed by adding improved bounds checking. The fix introduces validation of offset and length values derived from untrusted media file metadata before they are used in memory operations. Without these checks, attacker-controlled values in the file influence pointer arithmetic inside the affected component.

The attack requires local delivery of the file and user interaction. Exploitation does not require elevated privileges, since media files are processed in user-mode application contexts. The EPSS probability for in-the-wild exploitation stands at 0.024%, and the issue is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Root Cause

The underlying defect is missing or insufficient bounds validation when parsing fields inside a media container. Attacker-supplied size or offset values flow into read or write operations without verification against the actual buffer length, producing out-of-bounds access.

Attack Vector

An attacker delivers a crafted media file through email, messaging, web download, or removable media. When the user opens the file in a vulnerable Apple application, the media parser dereferences invalid memory. The result is either an application crash (denial of service) or controlled memory corruption that may enable follow-on exploitation.

No verified public proof-of-concept code is currently available. Refer to the Apple Support Advisory #125636 for vendor-confirmed technical context.

Detection Methods for CVE-2025-43338

Indicators of Compromise

Unexpected crashes or termination of media-handling applications such as QuickTime Player, Preview, or Photos on macOS and iOS
Generation of crash reports referencing media framework components (for example CoreMedia, AVFoundation, or image I/O libraries)
Receipt of unsolicited media files via email, messaging applications, or shared cloud storage

Detection Strategies

Monitor macOS endpoints for repeated ReportCrash entries naming media parsers within short time windows
Inspect mail and web gateways for inbound media files with malformed or anomalous container metadata
Correlate user-opened file events with subsequent application crash telemetry to surface targeted attempts

Monitoring Recommendations

Centralize macOS unified logs and crash diagnostics for retrospective hunting on media-processing exceptions
Track operating system and application versions across the fleet to confirm patch coverage for iOS 26, iPadOS 26, macOS Sonoma 14.8.2/14.8.4, and macOS Tahoe 26
Alert on execution of unsigned child processes spawned by media-handling applications following file opens

How to Mitigate CVE-2025-43338

Immediate Actions Required

Update affected devices to iOS 26, iPadOS 26, macOS Sonoma 14.8.2, macOS Sonoma 14.8.4, or macOS Tahoe 26
Restrict opening of media files received from untrusted sources until patches are deployed
Enforce mobile device management (MDM) policies that block installation of unpatched OS versions on enrolled endpoints

Patch Information

Apple released fixes that introduce improved bounds checking in the affected media parsing code. Patch details are documented in Apple Support Advisory #125108, Apple Support Advisory #125110, Apple Support Advisory #125636, and Apple Support Advisory #126350. Administrators should validate that all managed Apple devices report build numbers matching the fixed releases.

Workarounds

Disable automatic previews of media attachments in mail clients and messaging applications
Quarantine inbound media files at email and web gateways for sandbox analysis before delivery
Educate users to avoid opening unsolicited media files, particularly those with unusual extensions or sources

bash

# Verify macOS build to confirm patch deployment
sw_vers
# Expected ProductVersion: 14.8.2, 14.8.4, or 26.x for Tahoe

# Verify iOS/iPadOS build via MDM query or Settings > General > About
# Expected Software Version: 26.x or later