Detect CVE-2021-30952: Apple Multiple Products Integer Overflow Exploitation in Microsoft Sentinel
Detects exploitation attempts of CVE-2021-30952, an integer overflow vulnerability in Apple Multiple Products. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild. Integer overflow conditions in Apple platform components can lead to memory corruption, arbitrary code execution, or privilege escalation.
MITRE ATT&CK
KQL Detection Query
let lookback = 7d;
DeviceProcessEvents
| where Timestamp > ago(lookback)
| where DeviceType in ("MacOS", "iOS", "iPad")
| where (FileName in~ ("WebKit", "Safari", "MobileSafari", "com.apple.WebKit") or ProcessCommandLine has_any ("webkit", "JavaScriptCore", "WebCore"))
| where InitiatingProcessFileName !in~ ("softwareupdated", "mdmclient", "installd")
| extend RiskIndicator = case(
ProcessCommandLine has_any ("overflow", "heap spray", "shellcode"), "SuspiciousCommandArgs",
InitiatingProcessFileName has_any ("sh", "bash", "zsh") and FolderPath !startswith "/Applications", "ShellFromUnexpectedPath",
FileName has "crash" or ProcessCommandLine has "crash", "CrashIndicator",
"Unknown"
)
| where RiskIndicator != "Unknown"
| project Timestamp, DeviceName, DeviceType, AccountName, FileName, FolderPath, ProcessCommandLine, InitiatingProcessFileName, RiskIndicator
| order by Timestamp descDetects suspicious process behaviors on Apple devices consistent with CVE-2021-30952 integer overflow exploitation, focusing on WebKit and related Apple framework processes spawning unexpected child processes or exhibiting crash-like behavior.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate Safari or WebKit updates being applied via software update mechanisms
- Developer testing environments running WebKit debug builds
- Security research tools performing WebKit fuzzing or vulnerability testing
- Crash reporter processes legitimately collecting diagnostic information
Other platforms for CVE-2021-30952
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 Process Spawning Shell from Non-Standard Path
Expected signal: Process creation event showing /tmp/webkit-sim/WebContent spawning with process name matching WebContent but executing from /tmp path
- Test 2Create Persistence via LaunchAgent After Simulated WebKit Compromise
Expected signal: File creation event for plist in ~/Library/LaunchAgents/ followed by launchctl process execution loading the new agent
- Test 3Simulate Integer Overflow Memory Pressure via Safari Crash Report Generation
Expected signal: File creation event for .crash file in /tmp with WebContent prefix; potential file integrity monitoring alert
Unlock Pro Content
Get the full detection package for CVE-2021-30952 including response playbook, investigation guide, and atomic red team tests.