Detect CVE-2025-14733: WatchGuard Firebox Out-of-Bounds Write Exploitation in Google Chronicle
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
YARA-L Detection Query
rule watchguard_firebox_cve_2025_14733_exploitation {
meta:
author = "df00tech Detection Engineering"
description = "Detects CVE-2025-14733 WatchGuard Firebox out-of-bounds write exploitation"
severity = "CRITICAL"
priority = "HIGH"
reference = "https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00027"
yara_version = "YL2.0"
rule_version = "1.0"
events:
(
$e.metadata.vendor_name = "WatchGuard" nocase or
$e.metadata.product_name = "Firebox" nocase or
$e.principal.hostname = /.*firebox.*/i or
$e.principal.hostname = /.*watchguard.*/i
)
and
(
(
$e.metadata.description = /crash|segfault|SIGSEGV|core dump|out of bounds|buffer overflow|heap corruption|stack smashing/i
)
or
(
$e.target.port in (443, 4117, 4118, 8080) and
$e.security_result.severity = "CRITICAL"
)
)
condition:
$e
}Chronicle YARA-L rule detecting WatchGuard Firebox memory corruption events and high-severity management port activity consistent with CVE-2025-14733 exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Authorized security assessments producing crash or corruption indicators in Firebox logs
- Scheduled maintenance windows generating high-severity restart events on management ports
- Automated configuration management tools connecting frequently to management interfaces
- Firmware update processes triggering process termination with critical severity logs
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
Unlock Pro Content
Get the full detection package for CVE-2025-14733 including response playbook, investigation guide, and atomic red team tests.