CVE-2025-43446: 
macOS vulnerability analysis and mitigation

CVE-2025-43446 is a symlink validation vulnerability in Apple macOS that allows a low-privileged local application to modify protected parts of the file system. It was disclosed on November 3, 2025, as part of Apple's security updates for macOS Sonoma 14.8.2 and macOS Sequoia 15.7.2, with a subsequent fix also included in macOS Tahoe 26.1. Affected versions include macOS Sonoma prior to 14.8.2 and macOS Sequoia 15.0 through 15.7.1. The vulnerability was discovered by Zhongcheng Li from the IES Red Team of ByteDance and carries a CVSS v3.1 base score of 5.5 (Medium) (Apple Sequoia Advisory, Apple Sonoma Advisory).

The vulnerability is classified as CWE-59 (Improper Link Resolution Before File Access, or 'Link Following'), meaning the macOS Assets component fails to properly validate symbolic links before performing file operations, allowing an attacker to redirect file writes to protected system locations. An attacker with a low-privilege local account can craft a malicious symlink that, when followed by a privileged process, results in unauthorized writes to otherwise protected areas of the file system. No user interaction is required for exploitation, and the attack is confined to the local system. The fix involved improved validation of symlinks within the affected component (Apple Sequoia Advisory, Apple Sonoma Advisory).

Successful exploitation allows a low-privileged application to modify protected parts of the macOS file system without user interaction, potentially compromising system integrity. This could enable an attacker to tamper with critical system files, plant malicious content in protected directories, or undermine macOS security mechanisms such as System Integrity Protection (SIP) if the targeted paths are sufficiently sensitive. There is no direct confidentiality or availability impact per the CVSS assessment, but integrity compromise of protected file system areas could facilitate privilege escalation or persistence as a secondary effect (Apple Sequoia Advisory, Apple Sonoma Advisory).

As of the time of disclosure, there is no public proof-of-concept exploit and no evidence of in-the-wild exploitation (Feedly). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.018%, indicating a very low probability of exploitation in the near term. The attack requires local access with low privileges, which limits the attack surface compared to remotely exploitable vulnerabilities.

1. Gain local access: Obtain execution as a low-privileged user or app on a vulnerable macOS system (Sonoma < 14.8.2 or Sequoia 15.0–15.7.1).
2. Identify target path: Determine a protected file system location that the vulnerable Assets component accesses or writes to during normal operation.
3. Create malicious symlink: In a location writable by the attacker, create a symbolic link pointing from the expected file path to the desired protected target (e.g., ln -s /protected/system/file /tmp/attacker_controlled_path).
4. Trigger vulnerable code path: Execute or trigger the macOS Assets component (or a process that invokes it) so that it follows the attacker-controlled symlink without proper validation.
5. Achieve unauthorized write: The privileged process writes to the symlink destination — the protected file system location — effectively modifying protected system content with attacker-controlled data (Apple Sequoia Advisory, Apple Sonoma Advisory).

• File System: Unexpected symbolic links in directories writable by low-privileged users pointing to protected system paths (e.g., /System, /Library, /usr); unexpected modification timestamps on protected system files.
• Logs: Unified log entries from the Assets subsystem showing file operations on unusual or protected paths; macOS security audit logs (/var/audit) recording file write events to protected directories by non-privileged processes.
• Process: Unusual file write activity originating from low-privileged apps or sandboxed processes targeting system-protected directories.

Apple has released patches addressing this vulnerability in macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, and macOS Tahoe 26.1, all released on November 3, 2025. Users should update their macOS installations to these versions or later immediately. No configuration-based workaround is available; upgrading is the only remediation. Additionally, restricting local user privileges and monitoring file system integrity can reduce risk on systems that cannot be immediately patched (Apple Sequoia Advisory, Apple Sonoma Advisory, Apple Tahoe Advisory).

The CIS (Center for Internet Security) published an advisory noting multiple vulnerabilities in Apple products patched in this release cycle, including CVE-2025-43446, recommending prompt updates (CIS Advisory). The SANS Internet Storm Center also covered the November 2025 Apple patch batch in a diary entry. No significant independent researcher commentary or social media discussion specific to this CVE has been identified beyond standard vulnerability aggregation coverage.