CVE-2025-24188 Overview
CVE-2025-24188 is a logic flaw affecting Apple Safari and macOS Sequoia. Processing maliciously crafted web content can trigger an unexpected Safari crash, resulting in a denial of service condition. Apple addressed the issue through improved checks in Safari 18.6 and macOS Sequoia 15.6. The vulnerability requires user interaction, as a victim must visit or load attacker-controlled web content. The flaw is categorized under [CWE-703] (Improper Check or Handling of Exceptional Conditions). While the availability impact is high, the vulnerability does not compromise confidentiality or integrity of user data.
Critical Impact
Remote attackers can crash Safari by delivering crafted web content, disrupting browser availability across affected Apple platforms.
Affected Products
- Apple Safari (versions prior to 18.6)
- Apple macOS Sequoia (versions prior to 15.6)
- WebKit-based browsing on affected Apple operating systems
Discovery Timeline
- 2025-07-30 - CVE-2025-24188 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-24188
Vulnerability Analysis
The vulnerability stems from improper handling of exceptional conditions within Safari's web content processing pipeline. When Safari parses specifically crafted web content, a logic error causes the browser to terminate unexpectedly. The flaw affects the availability of the browsing session but does not allow arbitrary code execution or memory corruption based on Apple's advisory. Attackers can weaponize this by hosting malicious content on a website or embedding it in an iframe, ad network, or email preview. The bug is remotely reachable over the network and requires only that a user load the malicious page.
Root Cause
Apple's advisory describes the root cause as a logic issue addressed with improved checks. This maps to [CWE-703], indicating that Safari failed to validate or handle a specific input condition, leading to an abnormal termination. The fix introduces additional validation to reject or safely handle the malformed content path.
Attack Vector
Exploitation requires an attacker to lure a victim into loading crafted web content in Safari on an unpatched macOS or Safari installation. No authentication or elevated privileges are required. Successful exploitation crashes the Safari process, forcing the user to relaunch the browser and potentially losing session state or unsaved data. Repeated crashes could be used to prevent access to security-relevant web resources or to hinder incident response activities.
Detailed exploitation techniques were referenced in disclosures on the Full Disclosure mailing list. See the Full Disclosure July 2025 Post and Full Disclosure August 2025 Post for technical context.
Detection Methods for CVE-2025-24188
Indicators of Compromise
- Repeated Safari process crashes (com.apple.Safari) shortly after loading a specific URL or web page
- Crash reports in ~/Library/Logs/DiagnosticReports/ referencing Safari or WebKit components
- Users reporting reproducible Safari termination when visiting a specific site
Detection Strategies
- Monitor macOS endpoint telemetry for abnormal termination events of the Safari process and associated WebKit helpers.
- Correlate browser crash events with recently visited URLs from proxy or DNS logs to identify malicious hosts.
- Track Safari and macOS versions across the fleet to identify endpoints still running vulnerable builds.
Monitoring Recommendations
- Ingest macOS unified logs and crash reports into a centralized logging platform for anomaly analysis.
- Alert on clusters of Safari crash events across multiple users referencing the same destination domain.
- Track outbound web traffic to newly registered or low-reputation domains that coincide with browser crashes.
How to Mitigate CVE-2025-24188
Immediate Actions Required
- Update Safari to version 18.6 and macOS to Sequoia 15.6 or later on all managed Apple endpoints.
- Prioritize patching for users who routinely browse untrusted content or handle high-value data.
- Communicate the update requirement to users of unmanaged or BYOD Apple devices accessing corporate resources.
Patch Information
Apple released fixes in Safari 18.6 and macOS Sequoia 15.6. Refer to the vendor advisories at Apple Support Document #124149 and Apple Support Document #124152 for full remediation details and download instructions.
Workarounds
- Avoid browsing untrusted or unfamiliar websites in Safari until the patch is applied.
- Use an alternate, up-to-date browser for sensitive activity on unpatched macOS systems.
- Enforce web filtering policies that block known malicious or low-reputation domains at the network egress.
# Verify installed Safari and macOS versions on macOS
sw_vers
defaults read /Applications/Safari.app/Contents/Info CFBundleShortVersionString
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
