Detect CVE-2025-14733: WatchGuard Firebox Out-of-Bounds Write Exploitation in CrowdStrike LogScale
Detects exploitation attempts targeting CVE-2025-14733, an out-of-bounds write vulnerability (CWE-787) in WatchGuard Firebox devices. This vulnerability is actively exploited in the wild (CISA KEV) and may allow remote code execution or device compromise. Detection focuses on anomalous management interface activity, unexpected process crashes, and network indicators consistent with exploitation.
MITRE ATT&CK
- Tactic
- Initial Access Execution Impact
LogScale Detection Query
#event_simpleName IN ("NetworkConnectIP4", "NetworkConnectIP6", "ProcessRollup2", "SyntheticProcessRollup2")
| $vendor = "WatchGuard" OR $product = "Firebox" OR ComputerName = /.*firebox.*/i OR ComputerName = /.*watchguard.*/i
| (
CommandLine = /crash|segfault|SIGSEGV|core.dump|out.of.bounds|buffer.overflow|heap.corruption|stack.smashing/i
OR
(
RemotePort IN [443, 4117, 4118, 8080]
AND event_simpleName IN ("NetworkConnectIP4", "NetworkConnectIP6")
)
)
| groupby([ComputerName, UserName, RemoteAddressIP4, RemotePort, CommandLine])
| sort(count(), order=desc)CrowdStrike Falcon query detecting WatchGuard Firebox network connections to management ports and process anomalies indicative of CVE-2025-14733 out-of-bounds write exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate CrowdStrike-monitored systems performing authorized management of WatchGuard devices
- Security operations tools connecting to Firebox management interfaces for health monitoring
- Firmware update utilities triggering process-level events during planned maintenance
- Authorized penetration testers running exploit simulations against WatchGuard infrastructure
Other platforms for CVE-2025-14733
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 WatchGuard Management Interface Reconnaissance
Expected signal: Network connection logs showing SYN packets to ports 4117, 4118, 8080, and 443 from the attacker IP; IDS alerts on service enumeration; Firebox access logs showing connection attempts
- Test 2Malformed HTTP Request to Firebox Management Interface
Expected signal: Firebox crash or exception log entries; process termination events for web management daemon; syslog SIGSEGV or abnormal exit entries; network connection termination without proper HTTP response
- Test 3Post-Exploitation: Simulate Unauthorized Admin Account Creation Check
Expected signal: WatchGuard audit log entry for admin account creation; API access logs showing POST to user management endpoint; SIEM alert on privileged account creation on network device
Response Playbook
Triage
- Immediately verify whether affected WatchGuard Firebox devices have the latest firmware applied per WGSA-2025-00027 advisory. Cross-reference installed version against WatchGuard's patched releases.
- Identify all WatchGuard Firebox devices in the environment and their exposure level — determine which management interfaces (port 4117, 4118, 8080, 443) are internet-facing versus internal-only.
- Review Firebox device logs for crash events, unexpected process restarts, or abnormal terminations in the wgagent, wgrd, or httpd processes within the past 72 hours.
- Correlate source IPs of anomalous connections to management ports against threat intelligence feeds and check for repeat access patterns or scanning behavior.
- Determine if any post-exploitation indicators exist: new admin accounts, configuration changes, tunnels, or unexpected outbound connections from Firebox devices.
Containment
- Immediately restrict management interface access to known-good administrative IP ranges using ACLs or firewall rules, blocking all external/internet access to ports 4117, 4118, and 8080.
- If exploitation is confirmed or strongly suspected, isolate the affected Firebox device from the network by placing it in a quarantine VLAN or taking it offline, then bring up a backup or replacement device with the patched firmware.
- Rotate all WatchGuard administrative credentials including local admin accounts and any RADIUS/LDAP-integrated accounts used for device management.
- Block source IPs identified as exploitation actors at upstream network perimeter controls.
Evidence Collection
- Export full Firebox diagnostic logs, traffic logs, and event logs from the WatchGuard System Manager or web UI before any remediation steps that might overwrite them. Preserve timestamps and hash the archive.
- Capture network packet captures (PCAP) on spans/mirrors of management interfaces to preserve evidence of exploitation traffic, including any shellcode delivery or C2 callback patterns.
- Collect memory dumps or core dump files if the Firebox OS exposes them via diagnostic export — these may contain exploit payload artifacts useful for forensic analysis.
Escalation Criteria
- !Escalate immediately to incident response leadership if post-exploitation indicators are found: new unauthorized admin accounts, configuration changes to VPN policies, route injection, or unexpected traffic tunneled through the device.
- !Escalate to threat intelligence and executive leadership if the exploitation source is attributed to a nation-state actor or if multiple Firebox devices across the environment are simultaneously affected, indicating a coordinated campaign.
Investigation Guide
Related Techniques
Forensic Artifacts
- >
WatchGuard Firebox event logs (available via WSM or web UI): crash events, admin login attempts, policy changes - >
Core dump or diagnostic bundle files from affected Firebox devices (export via WatchGuard System Manager diagnostics) - >
Network PCAP on management interface ports (4117, 4118, 8080, 443) capturing exploitation payload structure - >
Syslog forwarded from Firebox to SIEM showing process termination events and kernel-level memory fault messages - >
Active VPN tunnel listings and any newly created policies or routes that may indicate post-exploitation persistence
Tuning Guidance
Start by baselining normal administrative access patterns to WatchGuard management interfaces — document the expected source IP ranges, access times, and connection frequencies for your environment. Raise thresholds for connection-count anomaly alerts to reduce false positives from monitoring tools. For crash/process termination detections, suppress known-good maintenance windows using time-based filters. If your Firebox devices forward syslog, validate that the process names (wgagent, wgrd, wguard) match your specific firmware version's actual process names, as they may differ across versions. Prioritize alerts where both a crash indicator AND anomalous source IP activity occur within the same 30-minute window, as this compound condition has much higher fidelity for true exploitation.
Hunting Queries
Hunts for high-frequency source IPs interacting with WatchGuard management interfaces over the past 7 days, enriched with threat intelligence, to identify scanning or exploitation campaigns targeting CVE-2025-14733.
CommonSecurityLog
| where DeviceVendor =~ "WatchGuard" or DeviceProduct =~ "Firebox"
| where TimeGenerated >= ago(7d)
| summarize EventCount = count(), FirstSeen = min(TimeGenerated), LastSeen = max(TimeGenerated) by SourceIP, Activity, DeviceAction
| where EventCount > 50
| join kind=leftouter (
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(30d)
| where isnotempty(NetworkIP)
| summarize TI_Description = make_set(Description) by NetworkIP
) on $left.SourceIP == $right.NetworkIP
| order by EventCount descindex=* sourcetype=watchguard earliest=-7d
| stats count AS event_count, earliest(_time) AS first_seen, latest(_time) AS last_seen BY src_ip, action, dest_port
| where event_count > 50
| eval risk_score = case(dest_port IN (4117, 4118, 8080), event_count * 2, dest_port == 443, event_count * 1.5, true(), event_count)
| sort -risk_score
| head 100Atomic Red Team Tests
Simulates an attacker performing reconnaissance against WatchGuard Firebox management interfaces to identify exposed services prior to CVE-2025-14733 exploitation. Lab environment only.
Command
nmap -sV -p 4117,4118,8080,443 --script http-title,ssl-cert <TARGET_FIREBOX_IP> -oN /tmp/watchguard_recon.txt && cat /tmp/watchguard_recon.txtCleanup
rm -f /tmp/watchguard_recon.txtExpected Telemetry
Network connection logs showing SYN packets to ports 4117, 4118, 8080, and 443 from the attacker IP; IDS alerts on service enumeration; Firebox access logs showing connection attempts
Expected Detection
KQL/SPL anomaly rules should trigger on connection volume to management ports; network IDS should alert on service fingerprinting activity
Sends malformed or oversized HTTP requests to the WatchGuard Firebox management web interface to simulate memory corruption trigger conditions similar to CVE-2025-14733. Lab environment only with isolated test device.
Command
python3 -c "
import socket, time
target = '<TARGET_FIREBOX_IP>'
port = 8080
payload = b'GET /' + b'A' * 65536 + b' HTTP/1.1\r\nHost: ' + b'B' * 8192 + b'\r\nContent-Length: 99999\r\n\r\n' + b'C' * 32768
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(10)
try:
s.connect((target, port))
s.send(payload)
response = s.recv(4096)
print('Response:', response[:200])
except Exception as e:
print('Exception (may indicate crash):', e)
finally:
s.close()
"Cleanup
No cleanup required; monitor target device for unexpected restart or crashExpected Telemetry
Firebox crash or exception log entries; process termination events for web management daemon; syslog SIGSEGV or abnormal exit entries; network connection termination without proper HTTP response
Expected Detection
Process crash detection rules in SIEM should fire; anomaly detection on management interface should alert on malformed request patterns
After simulated Firebox compromise, checks whether unauthorized administrator accounts were created as a persistence mechanism — validates that detection of T1136 (Create Account) on network devices is functional.
Command
curl -sk -X POST https://<TARGET_FIREBOX_IP>:8080/admin/users \
-H 'Content-Type: application/json' \
-H 'Authorization: Bearer <TEST_TOKEN>' \
-d '{"username": "test_backdoor_user", "role": "admin", "password": "TestP@ss123!"}' \
-o /tmp/account_creation_response.json && cat /tmp/account_creation_response.jsonCleanup
curl -sk -X DELETE https://<TARGET_FIREBOX_IP>:8080/admin/users/test_backdoor_user -H 'Authorization: Bearer <TEST_TOKEN>'; rm -f /tmp/account_creation_response.jsonExpected Telemetry
WatchGuard audit log entry for admin account creation; API access logs showing POST to user management endpoint; SIEM alert on privileged account creation on network device
Expected Detection
Privileged account creation detection rules should fire; WatchGuard administrative audit trail should record the event for SIEM ingestion