Detect Apple WebKit Use-After-Free Exploitation Attempt (CVE-2025-43529) in Elastic Security
Detects exploitation attempts targeting CVE-2025-43529, a use-after-free vulnerability in Apple's WebKit browser engine affecting multiple Apple products. This vulnerability is actively exploited in the wild (CISA KEV) and can lead to arbitrary code execution when a user visits a maliciously crafted webpage. Attackers may leverage this flaw to achieve initial access or privilege escalation on macOS, iOS, and iPadOS devices.
MITRE ATT&CK
Elastic Detection Query
sequence by host.id with maxspan=2m
[process where event.type == "start"
and process.name in ("Safari", "WebProcess", "com.apple.WebKit.WebContent")
and host.os.family == "macos"]
[process where event.type == "start"
and process.parent.name in ("Safari", "WebProcess", "com.apple.WebKit.WebContent")
and process.name in ("sh", "bash", "zsh", "python3", "curl", "osascript", "launchctl", "xterm", "nc", "ncat")]Elastic EQL sequence detection identifying a WebKit process followed within 2 minutes by a suspicious child process spawn, characteristic of CVE-2025-43529 exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Browser automation suites (Selenium, Playwright) running in non-sandboxed mode
- Legitimate macOS automation scripts triggered via browser UI
- MDM-initiated browser workflows that spawn helper processes
- Security product self-updates initiated through browser
Other platforms for CVE-2025-43529
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Simulate WebKit Child Process Spawn (macOS)
Expected signal: Process creation event: parent=osascript, child=bash; bash executing id and whoami commands
- Test 2WebProcess Curl Outbound Simulation
Expected signal: Network connection event: process=curl, initiated from simulated WebKit parent context, destination=127.0.0.1:9999
- Test 3Launchctl Persistence Attempt Post-WebKit Exploitation
Expected signal: Process creation: launchctl load with plist argument; file write to /tmp/webkit_test/test.plist; LaunchAgent registration event in macOS Unified Log
Unlock Pro Content
Get the full detection package for CVE-2025-43529 including response playbook, investigation guide, and atomic red team tests.