The recent release of macOS 15 ‘Sequoia’ has triggered unexpected connection problems and security concerns, particularly for users and businesses utilizing certain endpoint detection and response (EDR) software, virtual private networks (VPNs), and web browsers. Security tools like CrowdStrike Falcon and ESET Endpoint Security are reportedly encountering network disruptions when activated, raising red flags about their compatibility with Sequoia’s revamped networking architecture.

Additionally, VPNs like Mullvad and several corporate VPN solutions have been impacted, compromising secure connections and exposing both individuals and enterprises to significant security risks.

These issues seem to stem from alterations in Sequoia’s firewall and internal networking structures, which could lead to packet corruption, SSL failures, and DNS resolution breakdowns—critical vulnerabilities for businesses relying on these tools to safeguard sensitive data. Chrome and other Chromium-based browsers are also experiencing security-related failures like interrupted downloads, posing further risks for organizations.

While Apple has not addressed the concerns publicly, several security vendors have issued advisories and offered temporary solutions to mitigate the impact on defenses.

Why It Matters: macOS 15 ‘Sequoia’ brings substantial upgrades to Apple’s operating system, but also presents serious compatibility issues for essential security software and networking tools. For individuals and enterprises reliant on EDR and VPN solutions, these issues pose a significant risk to security and productivity. Until vendors and Apple release fixes, users, as well as corporate IT teams, may need to delay upgrading or implement temporary solutions.

• EDR and VPN Failures: Users of CrowdStrike Falcon, ESET Endpoint Security, and Mullvad VPN are experiencing network disruptions after upgrading to macOS Sequoia. These issues include SSL failures, corrupted packets, and DNS lookup failures.

• Browser Issues: Chrome and Chromium-based browsers are affected by these changes, with reports of interrupted downloads and DNS failures when using the firewall. Google has acknowledged the issue and is working on a fix.

• Vendor Warnings: CrowdStrike and SentinelOne have advised customers not to upgrade to macOS 15 until fixes are implemented. ESET provided a workaround for its users, though it is only applicable to newer software versions.

• Workarounds: Security researchers have proposed temporary solutions, including modifying firewall settings via command-line tools or disabling specific network filters. However, these fixes may only apply to certain configurations.

Go Deeper -> MacOS Sequoia Change Breaks Networking for VPN, Antivirus Software – Bleeping Computer

Apple’s macOS Sequoia Update Breaks Security Tools – HackRead