Detect Ubiquiti UniFi OS Improper Input Validation Vulnerability (CVE-2026-34910) in Google Chronicle
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
YARA-L Detection Query
rule cve_2026_34910_unifi_input_validation {
meta:
author = "df00tech Detection Engineering"
description = "Detects exploitation attempts for CVE-2026-34910 - Ubiquiti UniFi OS Improper Input Validation"
severity = "CRITICAL"
priority = "HIGH"
reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-34910"
events:
$e.metadata.event_type = "NETWORK_HTTP"
$e.target.port in (443, 8443, 8080, 80)
(
re.regex($e.network.http.request_url, `(?i)(\.\./|\.\.)%2[Ff]|%00|union.{0,10}select|exec\(|eval\(|cmd=|command=|wget\s|curl\s`) or
re.regex($e.network.http.request_body, `(?i)(cmd=|command=|exec\(|eval\(|union.{0,10}select|wget\s|curl\s)`)
)
(
re.regex($e.target.hostname, `(?i)(unifi|ubnt|ubiquiti|udm|usg|dream-machine)`) or
re.regex($e.target.asset.asset_id, `(?i)(ubiquiti|unifi)`)
)
condition:
$e
}Chronicle YARA-L rule detecting HTTP exploitation patterns targeting Ubiquiti UniFi OS devices, matching known input validation bypass strings in request URLs and bodies.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate administrative API calls with URL-encoded parameters from UniFi mobile applications
- Network management platforms that use complex query strings when polling UniFi device status
- Authorized vulnerability scanners with scheduled scan windows against UniFi infrastructure
- DevOps automation tools managing UniFi configurations via API with special character inputs
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
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