Detect Apple Multiple Products Classic Buffer Overflow Exploitation (CVE-2025-43520) in Splunk
Detects exploitation attempts targeting CVE-2025-43520, a classic buffer overflow vulnerability (CWE-120) affecting Apple Multiple Products. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild. Buffer overflow exploitation may manifest as abnormal process crashes, memory corruption signals, unexpected child process spawning from Apple system processes, or anomalous network connections following process exploitation.
MITRE ATT&CK
- Tactic
- Initial Access Execution Persistence
SPL Detection Query
index=mac_endpoints sourcetype IN (osquery:differential, jamf:events, crowdstrike:events:macos)
| eval apple_procs=mvappend("Safari", "com.apple.webkit", "coreaudiod", "imagent", "mediaserverd", "avatard", "bluetoothd", "configd", "AppleScript")
| where (event_type="process_crash" AND mvfind(apple_procs, process_name)>=0)
OR (event_type="process_create" AND mvfind(apple_procs, parent_process_name)>=0 AND child_process_name IN ("bash", "sh", "zsh", "python3", "perl", "osascript", "curl", "wget"))
OR (event_type="network_connection" AND mvfind(apple_procs, process_name)>=0 AND dest_port IN (4444, 1337, 31337, 8080, 8443))
| eval risk_signal=case(
event_type="process_crash", "ProcessCrash_PossibleOverflow",
event_type="process_create" AND child_process_name IN ("bash","sh","zsh"), "ShellSpawnedFromAppleProcess",
event_type="network_connection", "SuspiciousNetworkFromAppleProcess",
true(), "Unknown"
)
| stats count by _time, host, user, event_type, process_name, child_process_name, parent_process_name, dest_ip, dest_port, risk_signal
| sort -_timeSplunk query hunting for exploitation indicators of CVE-2025-43520 including Apple process crashes, unexpected shell spawning, and anomalous outbound connections from Apple system processes on macOS endpoints.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Legitimate Apple system updates causing transient process crashes
- IT automation scripts using AppleScript or osascript for management tasks
- Endpoint security tools initiating network connections from monitored Apple processes
- Development environments where Apple processes launch shell interpreters for legitimate testing
Other platforms for CVE-2025-43520
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 Shell Spawn from Apple-Like Parent Process
Expected signal: Process creation event showing osascript spawning bash; command line includes 'id' and 'hostname'.
- Test 2Simulate Suspicious Outbound Network Connection from Apple Process Context
Expected signal: Network connection attempt to port 4444 initiated by process tree rooted at osascript.
- Test 3Generate Apple Process Crash Report for Forensic Artifact Validation
Expected signal: Process crash event for bash with signal SIGSEGV; diagnostic report written to DiagnosticReports directory.
- Test 4Enumerate Persistence Mechanisms Post-Exploitation Simulation
Expected signal: File creation event for .plist file in ~/Library/LaunchAgents/; optional launchctl load event.
References (9)
- https://support.apple.com/en-us/125632
- https://support.apple.com/en-us/125633
- https://support.apple.com/en-us/125634
- https://support.apple.com/en-us/125635
- https://support.apple.com/en-us/125636
- https://support.apple.com/en-us/125637
- https://support.apple.com/en-us/125638
- https://support.apple.com/en-us/125639
- https://nvd.nist.gov/vuln/detail/CVE-2025-43520
Response Playbook
Triage
- Identify the specific Apple product and version on the affected host; cross-reference against Apple advisory pages (https://support.apple.com/en-us/125632 through 125639) to confirm whether the installed version is patched.
- Examine process crash logs on the affected macOS endpoint (Console.app, /Library/Logs/DiagnosticReports/, ~/Library/Logs/DiagnosticReports/) for crash signatures involving memory corruption or buffer overflow indicators in Apple processes.
- Review parent-child process relationships for any shell process (bash, sh, zsh, python3, osascript) spawned by an Apple system process around the time of the alert to assess post-exploitation activity.
- Check for any new persistence mechanisms (LaunchAgents, LaunchDaemons, Login Items, cron jobs) added to the affected macOS endpoint following the suspicious activity window.
- Correlate endpoint network logs for outbound connections to unusual destinations, especially on non-standard ports, originating from Apple system processes.
Containment
- If active exploitation is confirmed, isolate the affected macOS endpoint from the network using the EDR console (CrowdStrike network containment, Defender isolation) to prevent lateral movement or C2 communication.
- Force-update all Apple products on affected systems to the latest available version addressing CVE-2025-43520; prioritize devices showing crash or exploitation indicators.
- Block outbound connections from the affected host to identified suspicious IP addresses at the firewall or NAC layer while investigation is ongoing.
Evidence Collection
- Collect macOS diagnostic crash reports from /Library/Logs/DiagnosticReports/ and ~/Library/Logs/DiagnosticReports/ for the relevant Apple process; preserve them for memory corruption analysis.
- Export EDR telemetry for the affected device covering a 48-hour window around alert time, including process events, network connections, file write events, and scheduled task modifications.
- Capture a memory image of the affected process (if still running) using tools such as osxpmem or built-in macOS memory capture capabilities for forensic analysis.
Escalation Criteria
- !Escalate immediately if a shell process (bash, sh, osascript) is confirmed to have been spawned from a vulnerable Apple process, as this indicates successful exploitation and code execution.
- !Escalate if the affected endpoint shows signs of persistence mechanism creation, new user accounts, privilege escalation, or lateral movement following the initial alert, indicating a full compromise chain.
- !Escalate if multiple hosts in the environment show simultaneous exploitation indicators, suggesting a targeted campaign leveraging CVE-2025-43520.
Investigation Guide
Related Techniques
Forensic Artifacts
- >
macOS crash reports in /Library/Logs/DiagnosticReports/ containing EXC_BAD_ACCESS or EXC_BAD_INSTRUCTION for affected Apple processes - >
Unified Log entries (log show --predicate) showing unexpected Apple process terminations or memory fault signals - >
LaunchAgent or LaunchDaemon plist files created in /Library/LaunchAgents/, ~/Library/LaunchAgents/, or /Library/LaunchDaemons/ shortly after exploitation - >
Bash history or osascript execution logs on the affected user account indicating post-exploitation commands - >
Network flow records showing outbound connections from Apple processes to external IPs on unusual ports
Tuning Guidance
Reduce false positives by filtering known-good parent process hashes for Apple system processes matched against Apple's published code signatures. Whitelist specific MDM or management tool process trees (e.g., Jamf, Mosyle) that legitimately invoke shell interpreters via Apple frameworks. Tune network-based detections by excluding Apple CDN IP ranges and known software update server IPs from suspicious connection alerts. Consider adding a time-based correlation requiring both a process crash and subsequent shell spawn within 60 seconds for higher-confidence alerting.
Hunting Queries
Hunt for any historical instances of shell processes spawned from Apple system processes over the past 30 days, which could indicate prior exploitation attempts or compromises predating the alert.
DeviceProcessEvents
| where TimeGenerated >= ago(30d)
| where DeviceType == 'Mac'
| where InitiatingProcessFileName has_any ('coreaudiod', 'imagent', 'mediaserverd', 'avatard', 'bluetoothd', 'configd', 'Safari')
| where FileName in~ ('bash', 'sh', 'zsh', 'python3', 'perl', 'osascript', 'curl', 'wget', 'nc', 'ncat')
| summarize Count=count(), Hosts=dcount(DeviceName) by InitiatingProcessFileName, FileName, bin(TimeGenerated, 1d)
| order by Count descindex=mac_endpoints sourcetype=crowdstrike:events:macos event_type=ProcessCreate earliest=-30d
| where parent_process IN ("coreaudiod","imagent","mediaserverd","avatard","bluetoothd","configd","Safari")
AND child_process IN ("bash","sh","zsh","python3","perl","osascript","curl","wget","nc")
| stats count by parent_process, child_process, host, user
| sort -countAtomic Red Team Tests
Simulates post-exploitation behavior by launching a shell process with an Apple system process as parent, mimicking the observable artifact of a successful buffer overflow exploit in a vulnerable Apple product.
Command
osascript -e 'do shell script "bash -c \"id && hostname\""'Cleanup
No persistent artifacts; process exits after execution.Expected Telemetry
Process creation event showing osascript spawning bash; command line includes 'id' and 'hostname'.
Expected Detection
Alert triggered on shell process spawned from osascript (Apple scripting runtime), matching the ShellSpawnedFromAppleProcess risk signal.
Tests detection of anomalous outbound network connections on exploit-common ports originating from an Apple process context, emulating C2 beacon behavior following buffer overflow exploitation.
Command
osascript -e 'do shell script "curl -s --max-time 3 http://127.0.0.1:4444 || true"'Cleanup
No persistent changes; curl exits after timeout.Expected Telemetry
Network connection attempt to port 4444 initiated by process tree rooted at osascript.
Expected Detection
Alert on SuspiciousNetworkFromAppleProcess — connection to port 4444 from Apple process context.
Forces a crash of a test process to generate a diagnostic crash report in the macOS DiagnosticReports directory, validating that forensic artifact collection procedures and crash log monitoring are functioning correctly.
Command
bash -c 'cat /dev/urandom | head -c 1 > /dev/null; kill -SIGSEGV $$' || trueCleanup
Crash report generated in ~/Library/Logs/DiagnosticReports/; delete after test: rm ~/Library/Logs/DiagnosticReports/bash_*.crashExpected Telemetry
Process crash event for bash with signal SIGSEGV; diagnostic report written to DiagnosticReports directory.
Expected Detection
Crash monitoring alert fires on unexpected SIGSEGV in monitored process; diagnostic log artifact confirmed present for collection.
Simulates attacker post-exploitation persistence by installing a LaunchAgent plist, validating that detection and alerting for new LaunchAgent creation is operational on monitored macOS endpoints.
Command
cat > ~/Library/LaunchAgents/com.test.cve202543520.plist << 'EOF'
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0"><dict><key>Label</key><string>com.test.cve202543520</string><key>ProgramArguments</key><array><string>/bin/echo</string><string>test</string></array></dict></plist>
EOFCleanup
rm ~/Library/LaunchAgents/com.test.cve202543520.plist && launchctl bootout gui/$(id -u)/com.test.cve202543520 2>/dev/null || trueExpected Telemetry
File creation event for .plist file in ~/Library/LaunchAgents/; optional launchctl load event.
Expected Detection
File write detection for new LaunchAgent plist, correlated with the exploitation alert timeline to flag persistence establishment post-CVE-2025-43520 exploitation.