Full Report
Apple has issued 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 represents the seventh zero-day vulnerability that Apple has patched in 2025, underscoring the persistent and escalating threat landscape facing iOS and macOS devices. The vulnerability’s addition to CISA’s […] The post Analysis of Apple’s ImageIO Zero-Day Vulnerability: Attacker Context and Historical iOS Zero-Click Similarities appeared first on Cyber Security News.
Analysis Summary
# Vulnerability: Apple ImageIO Remote Code Execution via Malformed DNG File
## CVE Details
- CVE ID: CVE-2025-43300
- CVSS Score: Not explicitly stated, but context suggests **Critical** severity due to active exploitation and zero-click nature.
- CWE: Not explicitly stated, but related to memory safety/improper input validation (e.g., CWE-120/CWE-787).
## Affected Systems
- Products: Apple Ecosystem (iOS, macOS indicated by context)
- Versions: Not specified, but patches have been issued across the ecosystem.
- Configurations: Any configuration processing malicious DNG (Digital Negative) files via the ImageIO framework.
## Vulnerability Description
CVE-2025-43300 is an **out-of-bounds write vulnerability** residing within Apple’s **ImageIO framework**, specifically triggered during the JPEG lossless decoding logic for Adobe DNG files. The flaw arises from a metadata inconsistency: attackers modify the `SamplesPerPixel` value in the TIFF SubIFD (expecting a certain memory allocation) while simultaneously changing the component count in the JPEG SOF3 marker. The DNG decoder allocates memory based on the TIFF metadata but processes data based on the SOF3 marker, leading to a heap buffer overflow and enabling **arbitrary code execution**.
## Exploitation
- Status: **Actively exploited in the wild** (Targeted attacks)
- Complexity: **High** (Requires deep understanding of DNG format and ImageIO internals)
- Attack Vector: **Network** / Adjacent (Zero-click when processed via iMessage, email, AirDrop, or web content)
## Impact
- Confidentiality: High (Arbitrary Code Execution allows data exfiltration)
- Integrity: High (Arbitrary Code Execution allows system modification)
- Availability: High (System compromise)
## Remediation
### Patches
- Patches have been issued across the Apple ecosystem to address CVE-2025-43300 and it has been added to CISA's KEV catalog. (Specific version numbers are not provided in the text.)
### Workarounds
- No explicit workarounds are detailed in the provided text. Recommended action is immediate patching.
## Detection
- Detection tools such as **ELEGANT BOUNCER** have been developed that attempt to identify exploitation by validating consistency between metadata fields within image processing routines.
## References
- Vendor Advisory: Apple Security Updates (For CVE-2025-43300)
- CISA KEV Catalog: Remediation deadline of September 11, 2025.
- PoC Availability: Proof-of-concept code exists, demonstrating reproducibility by researcher b1n4r1b01.
- Relevant Links: hxxps://cybersecuritynews.com/apple-0-day-vulnerability-actively-exploited/