CVE-2026-7682 Overview
CVE-2026-7682 is a command injection vulnerability [CWE-74] affecting the Edimax BR-6208AC router, firmware version 1.02. The flaw resides in the setWAN function within /goform/setWAN, specifically in the L2TP Mode component. Attackers manipulate the L2TPUserName argument to inject operating system commands. The vulnerability is exploitable remotely over the network and requires low privileges. Public exploit code has been released, increasing the practical risk to exposed devices. Edimax was notified prior to disclosure but did not respond.
Critical Impact
Authenticated remote attackers can inject arbitrary commands through the L2TPUserName parameter, gaining control over affected Edimax BR-6208AC routers running firmware 1.02.
Affected Products
- Edimax BR-6208AC router
- Firmware version 1.02 (V2)
- L2TP Mode WAN configuration component
Discovery Timeline
- 2026-05-03 - CVE-2026-7682 published to NVD
- 2026-05-05 - Last updated in NVD database
Technical Details for CVE-2026-7682
Vulnerability Analysis
The vulnerability is a classic command injection issue in the router's web management interface. The setWAN handler at /goform/setWAN accepts user-supplied input through the L2TPUserName parameter when configuring an L2TP WAN connection. The parameter value is passed to a system shell without proper sanitization or quoting. An attacker who can authenticate to the web interface can embed shell metacharacters within the username field to execute arbitrary commands on the underlying Linux operating system. Successful exploitation typically yields code execution under the privileges of the web server process, which on consumer routers is frequently root.
The weakness is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). EPSS data places the probability of exploitation in the wild at 1.058% (77th percentile), reflecting available public exploit material.
Root Cause
The root cause is missing input validation and unsafe construction of shell commands. The setWAN function concatenates the L2TPUserName value into a command string passed to a system call such as system() or popen(). Shell metacharacters including ;, |, &, and backticks are not stripped or escaped, allowing command separation and chaining.
Attack Vector
Exploitation requires network access to the router's HTTP management interface and valid low-privilege credentials. The attacker submits a crafted POST request to /goform/setWAN with a malicious payload in the L2TPUserName field. The router executes the injected command during WAN configuration processing. Because routers are often exposed on management VLANs or, in misconfigured deployments, the WAN interface, remote exploitation is feasible. Public exploit details are documented in the Notion Command Injection Report and VulDB Vulnerability #360841.
See the linked technical references for the specific payload structure and request format.
Detection Methods for CVE-2026-7682
Indicators of Compromise
- HTTP POST requests to /goform/setWAN containing shell metacharacters such as ;, |, &, $(), or backticks within the L2TPUserName parameter.
- Unexpected outbound connections originating from the router to attacker-controlled infrastructure following WAN reconfiguration events.
- New or modified processes on the router that were not spawned by legitimate administrative activity.
Detection Strategies
- Inspect web server access logs on the router for requests to /goform/setWAN with anomalous L2TPUserName values exceeding expected length or containing non-alphanumeric characters.
- Deploy network intrusion detection signatures matching command injection payloads in HTTP request bodies destined for router management interfaces.
- Correlate router configuration changes with authentication events to identify unauthorized L2TP WAN modifications.
Monitoring Recommendations
- Monitor egress traffic from routers and network appliances for connections to unfamiliar IP addresses or suspicious ports.
- Alert on management interface access from untrusted source networks, particularly the WAN side.
- Track firmware versions across the device fleet to identify unpatched Edimax BR-6208AC units running version 1.02.
How to Mitigate CVE-2026-7682
Immediate Actions Required
- Restrict access to the router's web management interface to trusted internal management networks only; never expose it to the WAN.
- Change default and weak credentials on all Edimax BR-6208AC devices to prevent low-privilege account abuse.
- Audit existing L2TP WAN configurations for tampering and reset suspicious entries.
- Consider replacing affected devices given the lack of vendor response to the disclosure.
Patch Information
No vendor patch is available at the time of publication. The vendor was contacted prior to public disclosure but did not respond. Organizations should track the VulDB Vulnerability #360841 entry for any future advisory updates from Edimax.
Workarounds
- Disable the web management interface on the WAN side and bind it exclusively to the LAN management VLAN.
- Place affected routers behind a firewall that filters HTTP/HTTPS access to /goform/* endpoints from untrusted sources.
- Avoid using L2TP WAN mode on this device until a vendor fix is published; switch to alternative WAN connection types where feasible.
- Segment IoT and network infrastructure devices from production user and server networks to contain potential compromise.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
