Detect Ubiquiti UniFi OS Improper Input Validation Vulnerability (CVE-2026-34910) in Sumo Logic CSE
Detects exploitation attempts targeting CVE-2026-34910, an improper input validation vulnerability in Ubiquiti UniFi OS. This vulnerability is listed on CISA's Known Exploited Vulnerabilities catalog and allows attackers to send malformed or unexpected input to UniFi OS network management interfaces, potentially leading to unauthorized access, command execution, or device compromise. UniFi OS powers a wide range of Ubiquiti network devices including Dream Machines, Cloud Keys, and network switches used in enterprise and SMB environments.
MITRE ATT&CK
Sumo Detection Query
_sourceCategory=network/firewall OR _sourceCategory=network/proxy OR _sourceCategory=ids/alerts
| where _raw matches /(?i)(unifi|ubnt|ubiquiti|udm|usg)/
| parse regex field=url "(?<suspicious_segment>(\.\./|\.\.%2[Ff]|%00|union.{0,5}select|exec\(|eval\(|cmd=|command=|wget\s|curl\s))" nodrop
| where !isNull(suspicious_segment) and suspicious_segment != ""
| fields src_ip, dest_ip, dest_port, url, method, status_code, suspicious_segment
| stats count AS attempt_count, dcount(url) AS unique_paths, values(suspicious_segment) AS observed_patterns by src_ip, dest_ip, dest_port
| where attempt_count > 3
| sort by attempt_count descSumo Logic query identifying malformed input patterns in HTTP traffic targeting Ubiquiti UniFi OS management interfaces, flagging sources with multiple exploitation attempts.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate UniFi controller software making API calls with complex authentication tokens
- Authorized red team exercises targeting network infrastructure
- Third-party integration tools connecting to UniFi APIs with URL-encoded special characters
- Backup solutions that enumerate UniFi device configuration endpoints
Other platforms for CVE-2026-34910
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 1CVE-2026-34910 Path Traversal Probe Against UniFi OS API
Expected signal: HTTP requests with path traversal sequences ('../', '%2f') in URL paths to port 443 should appear in web proxy logs, firewall logs, and IDS/IPS alerts
- Test 2CVE-2026-34910 Command Injection Parameter Fuzzing
Expected signal: HTTP GET requests containing command injection strings (cmd=, command=, exec(), eval()) in query parameters to port 8443 visible in network logs
- Test 3CVE-2026-34910 Authenticated API Manipulation with Malformed Input
Expected signal: POST/PUT requests with SQL injection and command injection strings in JSON body fields to UniFi OS API endpoints; authentication attempts with malformed username fields
References (4)
- https://community.ui.com/releases/Security-Advisory-Bulletin-064-064/84811c09-4cf4-42ab-bd61-cc994445963b
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2026-34910
Unlock Pro Content
Get the full detection package for CVE-2026-34910 including response playbook, investigation guide, and atomic red team tests.