CVE-2025-30425 Overview
CVE-2025-30425 is a privacy vulnerability affecting Apple Safari and multiple Apple operating systems. A malicious website can track users while they browse in Safari's private browsing mode. Apple addressed the issue through improved state management across Safari and its underlying platforms.
The flaw is categorized under [CWE-284] (Improper Access Control) and requires user interaction, such as visiting an attacker-controlled webpage. While the vulnerability does not enable code execution or data modification, it undermines the privacy guarantees that users expect from Safari's private browsing mode.
Critical Impact
A malicious website may bypass Safari private browsing isolation to persistently track users across sessions, defeating a core privacy control on iOS, iPadOS, macOS, tvOS, and watchOS.
Affected Products
- Apple Safari (prior to 18.4)
- Apple iOS 18.4, iPadOS 18.4, and iPadOS 17.7.6
- Apple macOS Sequoia 15.4, tvOS 18.4, and watchOS 11.4
Discovery Timeline
- 2025-03-31 - CVE-2025-30425 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-30425
Vulnerability Analysis
The vulnerability resides in how Safari manages internal state between private browsing sessions and other browser contexts. Improper state isolation allows a malicious website to persist identifying signals that should be discarded when a private browsing window is used. Apple's advisory attributes the fix to improved state management, indicating that browser state components were leaking or persisting across the private/normal boundary.
Safari's private browsing mode is designed to prevent websites from correlating a user's activity with prior sessions. When state management fails, an attacker-controlled site can re-identify a returning visitor. This affects the WebKit-based browsing stack shared across iOS, iPadOS, macOS, tvOS, and watchOS, extending the impact well beyond the desktop Safari client.
Root Cause
The root cause is improper access control [CWE-284] over browser state that should be scoped exclusively to a private browsing session. State elements were accessible or reconstructable from contexts that should not have visibility into private-mode identifiers. Apple's remediation reworked the internal state lifecycle so that private browsing contexts no longer expose trackable artifacts.
Attack Vector
Exploitation requires the victim to load a malicious webpage over the network in Safari, including within a private browsing window. The attacker relies on client-side techniques to read or infer persistent state values. No authentication or elevated privileges are required, and the attack does not compromise confidentiality of user data beyond enabling tracking.
No public proof-of-concept has been released, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. For technical background, refer to the Apple Support Document #122371 and related advisories.
Detection Methods for CVE-2025-30425
Indicators of Compromise
- Safari or WebKit-based application versions predating iOS/iPadOS 18.4, iPadOS 17.7.6, macOS Sequoia 15.4, tvOS 18.4, or watchOS 11.4.
- Outbound connections from Safari private browsing sessions to domains associated with fingerprinting or tracking infrastructure.
- Repeat visits from the same device to a suspected tracking domain that yield consistent client-side identifiers despite private mode being enabled.
Detection Strategies
- Inventory managed Apple endpoints and compare installed OS and Safari versions against the fixed builds listed in Apple's advisories.
- Inspect web proxy or DNS logs for connections to known tracking, fingerprinting, or analytics endpoints originating from managed devices.
- Use mobile device management (MDM) reporting to identify devices that have not received the March 2025 Apple security updates.
Monitoring Recommendations
- Track patch compliance for iOS, iPadOS, macOS, tvOS, and watchOS across the fleet, prioritizing devices used to access sensitive web applications.
- Alert when devices running vulnerable Safari versions authenticate to corporate SaaS applications where session identity integrity matters.
- Monitor for the disclosure of new proof-of-concept code referencing CVE-2025-30425 via threat intelligence feeds.
How to Mitigate CVE-2025-30425
Immediate Actions Required
- Update all Apple devices to Safari 18.4, iOS 18.4, iPadOS 18.4 (or iPadOS 17.7.6 on older hardware), macOS Sequoia 15.4, tvOS 18.4, and watchOS 11.4.
- Enforce minimum OS versions through MDM policies to block non-compliant devices from accessing corporate resources.
- Advise privacy-sensitive users not to rely on private browsing on unpatched devices for tracking-resistant browsing.
Patch Information
Apple released fixes on March 31, 2025 across the affected platforms. Consult the vendor advisories for build numbers and release notes: Apple Support #122371, #122372, #122373, #122377, and #122379.
Workarounds
- Use content-blocking extensions and tracker-blocking DNS resolvers to reduce exposure to fingerprinting scripts on unpatched devices.
- Disable JavaScript for untrusted sites in Safari settings when strict privacy is required and patching is not yet possible.
- Restrict browsing of sensitive workflows to fully patched, managed endpoints until all devices are updated.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
