Detect Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700) in Microsoft Sentinel
Detects exploitation attempts and post-exploitation activity related to CVE-2026-20700, a buffer overflow vulnerability (CWE-119) affecting multiple Apple products. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild. Buffer overflow exploitation against Apple platforms may result in arbitrary code execution, privilege escalation, or sandbox escape.
MITRE ATT&CK
KQL Detection Query
let timeframe = 24h;
DeviceEvents
| where Timestamp > ago(timeframe)
| where DeviceType == "AppleDevice" or OSPlatform has_any ("macOS", "iOS", "iPadOS")
| where ActionType in ("ExploitGuardNonMicrosoftSignedBlocked", "MemoryAllocationViolationBlocked", "ProcessInjection", "ShellcodeExecution")
| project Timestamp, DeviceName, AccountName, ActionType, FileName, ProcessCommandLine, RemoteIP, RemotePort
| union (
DeviceProcessEvents
| where Timestamp > ago(timeframe)
| where OSPlatform has_any ("macOS", "iOS", "iPadOS")
| where ProcessCommandLine has_any ("heap spray", "rop chain") or (InitiatingProcessFileName in~ ("Safari", "WebKit", "com.apple.webkit", "MobileSafari") and FileName in~ ("sh", "bash", "zsh", "python", "python3", "osascript", "launchctl"))
| project Timestamp, DeviceName, AccountName, ActionType="SuspiciousChildProcess", FileName, ProcessCommandLine, RemoteIP="", RemotePort=0
)
| extend Severity = "High"
| extend CVE = "CVE-2026-20700"
| order by Timestamp descDetects memory violation events and suspicious process spawning from Apple platform browser or webkit processes that may indicate CVE-2026-20700 exploitation. Unions device exploit guard events with suspicious child process creation from Apple browser components.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate developer tools or debuggers triggering memory instrumentation alerts on macOS
- Security testing tools or penetration testing activities on Apple devices in managed environments
- Legitimate automation scripts launched by browser extensions with elevated privileges
- Memory profiling or performance analysis tools generating similar telemetry
Other platforms for CVE-2026-20700
Testing Methodology
Validate this detection against 4 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: EDR should log process creation event with parent process name matching 'com.apple.WebKit.WebContent' spawning 'bash' with shell commands. Network telemetry should show no external connections in this baseline test.
- Test 2Simulate Post-Exploitation Persistence via LaunchAgent (macOS)
Expected signal: File creation event in ~/Library/LaunchAgents/ with a plist filename mimicking Apple system components. EDR should log the file write and potentially the LaunchAgent registration.
- Test 3Simulate Exploit Attempt Network Callback (macOS)
Expected signal: Network connection attempt from curl process with unusual User-Agent string. In production scenario, this would be replaced with the WebKit process making the network connection directly.
- Test 4Heap Spray Pattern Simulation via Python (macOS/Linux)
Expected signal: Python process allocating large contiguous memory blocks in rapid succession. Memory allocation anomaly detection in EDR should generate telemetry showing large heap allocations.
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Get the full detection package for CVE-2026-20700 including response playbook, investigation guide, and atomic red team tests.