**In-Depth Analysis of Apple’s ImageIO Zero-Day Vulnerability: Understanding the Attacker Landscape and Historical Parallels with iOS Zero-Click Exploits** This comprehensive examination delves into Apple’s ImageIO zero-day vulnerability, exploring the context of potential attackers and drawing historical comparisons with previous iOS zero-click vulnerabilities. By analyzing the implications of this security flaw, we aim to shed light on the evolving threat landscape and the tactics employed by cybercriminals. Discover the critical insights that can help users and developers safeguard their devices against similar exploits in the future.
Apple has released emergency security updates across its entire ecosystem to address CVE-2025-43300, a critical zero-day vulnerability in the ImageIO framework that has been actively exploited in sophisticated targeted attacks. This marks the seventh zero-day vulnerability that Apple has patched in 2025, highlighting the persistent and escalating threat landscape facing iOS and macOS devices. The vulnerability’s inclusion in the Cybersecurity and Infrastructure Security Agency’s (CISA) Known Exploited Vulnerabilities (KEV) catalog, with a remediation deadline of September 11, 2025, underscores the urgent operational risk it poses to both organisations and individual users. CVE-2025-43300 is an out-of-bounds write vulnerability that specifically targets the JPEG lossless decoding logic for Adobe DNG (Digital Negative) files.
The vulnerability arises from a critical inconsistency between metadata declarations in TIFF subdirectories and the actual component count in JPEG SOF3 (Start of Frame 3) markers. Attackers can exploit this vulnerability by manipulating just two bytes in a legitimate DNG file to create a dangerous metadata mismatch. Security researchers have demonstrated that modifying the SamplesPerPixel value from 1 to 2 in the TIFF SubIFD at offset 0x2FD00, while simultaneously changing the SOF3 component count from 2 to 1 at offset 0x3E40B, can trigger memory corruption during image processing. When Apple’s DNG decoder processes this malformed file, it allocates memory based on the SamplesPerPixel metadata, expecting 2 components, but processes data according to the SOF3 component count, which only has 1 component. This results in a heap buffer overflow that enables arbitrary code execution, allowing for zero-click exploitation through iMessage, email attachments, AirDrop transfers, or web content.
Categories: Security Vulnerabilities, Exploit Techniques, Threat Landscape
Tags: Apple, Security, CVE-2025-43300, Zero-Day, Vulnerability, ImageIO, Exploitation, JPEG, Memory Corruption, DNG