CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability

This vulnerability is a classic buffer overflow present in multiple Apple operating systems. A malicious application could exploit it to force unexpected system termination or perform writes to kernel memory.

How it works

The weakness is identified as CWE-120. In this class of flaw, an application fails to properly validate the size of data written into a fixed-length buffer.

• An attacker-controlled application supplies input that exceeds the buffer boundary.
• Successful abuse can corrupt adjacent memory structures, resulting in either a crash or unauthorized writes into kernel address space.
• Exploitation requires execution of the malicious application on the affected device; no further details on attack mechanics are provided in the available summary.

Am I affected? How to find it in your systems

The vulnerability affects Apple watchOS, iOS, iPadOS, macOS, visionOS, and tvOS. Begin by inventorying all managed and unmanaged devices running these operating systems, including mobile, desktop, and embedded deployments.

• Query device management consoles or endpoint inventories for the presence of the listed Apple platforms.
• Compare installed versions and configurations against the exact criteria listed in the vendor advisory, as not every release is necessarily impacted.
• Review system logs for repeated unexpected terminations of processes or kernel-level errors that lack other explanations.

How to remediate

Apply the vendor-supplied update referenced in the official Apple advisory. This is the primary and most effective action.

• Follow the installation and verification steps provided by Apple for each affected platform.
• After patching, confirm that the update has been applied across the device fleet using your existing management tooling.

If you can't patch immediately

Apply mitigations according to the vendor instructions. Where cloud services are involved, follow applicable BOD 22-01 guidance. If mitigations cannot be implemented, discontinue use of the affected product.

• Restrict installation of untrusted applications through configuration profiles or mobile device management policies.
• Monitor endpoint telemetry for anomalous process behavior or repeated crashes on unpatched devices.
• Segment high-risk devices from sensitive networks until updates can be deployed.

If your data may have been exposed

Actively exploited vulnerabilities of this type have led to data breaches in other incidents. You can run a free exposure scan of your email addresses against known breach data to check for prior compromises.