CVE-2025-43279 Overview
CVE-2025-43279 is a privacy vulnerability in Apple macOS where system log entries insufficiently redact private data. A local application can read log entries and retrieve user-sensitive information that should have been masked. Apple addressed the issue by improving private data redaction for log entries in macOS Tahoe 26. The weakness is categorized under [CWE-359: Exposure of Private Personal Information to an Unauthorized Actor]. Exploitation requires local access with no user interaction and no privileges, making it viable for unprivileged apps installed on the host.
Critical Impact
An installed app can access user-sensitive data by reading log entries that failed to redact private information.
Affected Products
- Apple macOS versions prior to macOS Tahoe 26
- Applications relying on the unified logging subsystem for diagnostic data
- Local user sessions on affected macOS builds
Discovery Timeline
- 2025-09-15 - CVE-2025-43279 published to the National Vulnerability Database
- 2025-09-15 - Apple publishes the security advisory for macOS Tahoe 26
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-43279
Vulnerability Analysis
The flaw resides in how macOS handles private data markers within log entries generated by the unified logging system. Log messages authored with %{private} or similar formatting directives should have their sensitive values redacted before persisting to disk or being surfaced through log APIs. In affected macOS releases, these redactions were incomplete, allowing sensitive fields to appear in cleartext within log stores accessible to local processes.
The vulnerability falls under [CWE-359], covering exposure of private personal information. Impact is limited to confidentiality; the flaw does not modify data or interrupt service. Apple resolved the issue in macOS Tahoe 26 by improving the private data redaction path for log entries.
Root Cause
The root cause is inconsistent enforcement of privacy markers in the log formatter. Certain code paths persisted private substitutions without applying the redaction filter, leaving user-sensitive strings intact in log archives and streaming APIs consumable by local apps.
Attack Vector
An attacker delivers a signed or unsigned application to the target macOS system through standard distribution channels. Once launched by the user, the app enumerates local log entries using public logging interfaces such as log show, OSLogStore, or lower-level log archive reads. The app parses returned entries for the unredacted private fields and exfiltrates the harvested user-sensitive data. No elevation of privilege and no additional user interaction beyond running the app is required.
No public proof-of-concept code has been published for this issue. See the Apple Support Document and the Full Disclosure Security Post for advisory-level detail.
Detection Methods for CVE-2025-43279
Indicators of Compromise
- Unexpected processes invoking log show, log collect, or reading files under /var/db/diagnostics/ and /var/db/uuidtext/.
- Applications linking OSLog.framework or OSLogStore APIs without a legitimate diagnostic use case.
- Outbound network transfers immediately following bulk log enumeration by non-system binaries.
Detection Strategies
- Baseline which signed binaries legitimately access the unified log store and alert on deviations from that allowlist.
- Monitor endpoint telemetry for command-line invocations of log show --predicate from user-space, non-administrative processes.
- Correlate log-store access events with file exfiltration or DNS beaconing patterns to identify staged data theft.
Monitoring Recommendations
- Enable macOS Endpoint Security framework subscribers to record file opens against /var/db/diagnostics/* paths.
- Track macOS version inventory to identify hosts still running builds earlier than macOS Tahoe 26.
- Review Transparency, Consent, and Control (TCC) prompts and installed application entitlements for apps requesting broad file system access.
How to Mitigate CVE-2025-43279
Immediate Actions Required
- Upgrade all Mac endpoints to macOS Tahoe 26 or later, which contains the corrected log redaction logic.
- Audit installed third-party applications and remove any that lack a verified publisher or legitimate business use.
- Restrict standard users from installing unvetted applications by enforcing Gatekeeper and application allowlisting.
Patch Information
Apple resolved CVE-2025-43279 in macOS Tahoe 26 by improving private data redaction for log entries. Administrators should deploy the update through Apple Software Update, MDM, or their patch management workflow. Refer to the Apple Support Document for the full advisory and build numbers.
Workarounds
- Limit distribution of unified log archives from affected hosts until patched, including support bundles and sysdiagnose outputs.
- Enforce least-privilege application installation policies through MDM configuration profiles.
- Rotate any credentials or tokens that may have surfaced in log entries prior to patching.
# Verify macOS build and confirm patched status
sw_vers
# List recent log entries to review potential private-data exposure before upgrading
sudo log show --last 1h --style syslog --predicate 'eventType == logEvent'
# Restrict log archive access to administrators (example)
sudo chmod 750 /var/db/diagnostics
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.