Detect CVE-2021-30952: Apple Multiple Products Integer Overflow Exploitation in Google Chronicle
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
YARA-L Detection Query
rule cve_2021_30952_apple_integer_overflow {
meta:
author = "df00tech Detection Engineering"
description = "Detects potential exploitation of CVE-2021-30952 Apple integer overflow vulnerability"
severity = "HIGH"
priority = "HIGH"
reference = "https://nvd.nist.gov/vuln/detail/CVE-2021-30952"
events:
$e.metadata.event_type = "PROCESS_LAUNCH"
$e.principal.platform = "MAC"
(
$e.target.process.file.full_path = /\/com\.apple\.WebKit\.WebContent/ nocase or
$e.target.process.file.full_path = /\/Safari/ nocase or
$e.target.process.file.full_path = /\/MobileSafari/ nocase
)
not $e.target.process.file.full_path = /^\/Applications\// nocase
not $e.target.process.file.full_path = /^\/System\// nocase
not $e.principal.process.file.full_path = /^\/System\/Library\// nocase
not $e.principal.process.file.full_path = /\/launchd/ nocase
condition:
$e
}Chronicle YARA-L rule detecting WebKit and Safari process launches from non-standard paths on macOS, indicative of post-exploitation activity following CVE-2021-30952 integer overflow exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Enterprise applications installing WebKit components to non-standard directories
- Developer builds of Safari or WebKit launched during application testing
- Security research environments with modified Apple software paths
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
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