CVE-2025-43300 in iOS
Summary
by MITRE • 08/21/2025
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS 15.8.5, iOS 16.7.12 and iPadOS 16.7.12. Processing a malicious image file may result in memory corruption. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals.
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Analysis
by VulDB Data Team • 11/07/2025
The vulnerability identified as CVE-2025-43300 represents a critical out-of-bounds write flaw that affects Apple's iOS and iPadOS operating systems. This issue stems from insufficient bounds checking during the processing of image files, creating a potential avenue for memory corruption attacks. The vulnerability manifests when the system attempts to handle maliciously crafted image data, where improper input validation allows unauthorized memory access beyond allocated boundaries. Security researchers have classified this as a serious concern due to its potential for remote code execution and system compromise.
The technical nature of this vulnerability aligns with CWE-787, which specifically addresses out-of-bounds write conditions in software systems. This flaw operates at the memory management level where image parsing routines fail to properly validate array indices or buffer limits before writing data. When processing malformed image files, the system's image decoder does not adequately verify the size constraints of the input data against the allocated memory buffers, creating opportunities for attackers to manipulate memory contents. The vulnerability is particularly dangerous because it can be triggered through routine image processing operations, making it difficult to detect and prevent.
The operational impact of CVE-2025-43300 extends beyond typical security concerns due to documented evidence of active exploitation in targeted attacks. Apple has confirmed that this vulnerability has been exploited in extremely sophisticated campaigns against specific individuals, indicating that threat actors have developed advanced techniques to leverage this memory corruption flaw. The attack vector involves delivering malicious image files through various channels including email attachments, messaging applications, or web downloads, where the simple act of viewing or processing the image triggers the exploit. This targeted exploitation pattern suggests the vulnerability may be used in advanced persistent threat campaigns or nation-state attacks.
Organizations and users must implement immediate mitigation strategies to protect against this vulnerability. The most effective solution involves deploying the available security updates from Apple, specifically iOS 15.8.5 and iPadOS 15.8.5, as well as iOS 16.7.12 and iPadOS 16.7.12, which contain the necessary bounds checking improvements. System administrators should prioritize patch management and ensure all devices receive these updates promptly. Additional protective measures include implementing strict file validation policies, particularly for image files from untrusted sources, and deploying network monitoring tools to detect potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1059.007 for Windows Image File Execution Options and similar techniques, though the specific memory corruption methods require tailored defensive approaches. Security teams should also consider implementing sandboxing mechanisms and restricting image processing capabilities in high-risk environments to minimize potential impact from successful exploitation attempts.