CVE-2017-14942

Think of this bug like someone being able to grab the router’s “backstage manual” without permission. If they get that file, they can figure out how to get in as an administrator and take control of the router.

For a small business, that’s similar to handing an unknown person a master key to your building’s main door.

This matters to you if you run an Intelbras WRN 150 router and that device is reachable from the internet. The available information indicates the attack uses a direct request to a specific router file/CGI endpoint.

If your WRN 150 is not exposed to the internet (for example, only accessible from your local network), the practical risk is much lower; the main concern is internet reachability of the router’s services needed for the request.

This is RED because there is a public exploit available and attackers are actively able to carry out the attack once the device is reachable. With no vendor fix details found in the available sources, you need to treat mitigation/restriction as urgent rather than waiting.

Act now to reduce internet exposure and determine whether a firmware update exists for your exact WRN 150 firmware.

1. Confirm exposure and device match

   • Verify the router model is Intelbras WRN 150.
   • Check the firmware version shown in the router’s admin interface.
   • Determine whether your router is reachable from the internet (for example, whether you can access its admin/web interface from outside your network, or whether inbound WAN rules allow it).

2. Attempting to verify (only if your IT can do it safely)

   • This vulnerability involves a direct request to a CGI path: cgi-bin/DownloadCfg/RouterCfm.cfg.
   • If you have internal scanning tools, your IT team can test from an external network/host to see whether that endpoint is accessible and returns configuration content.
   • If you find it accessible, treat it as confirmed exposure and proceed immediately to containment.

3. Containment while waiting for a fix

   • Block inbound internet traffic to the router’s web/CGI endpoints at your firewall (or upstream firewall).
   • Specifically deny access to cgi-bin/DownloadCfg/RouterCfm.cfg (and, at minimum, deny inbound access to router management/HTTP/CGI services from the internet).
   • If you currently allow remote administration, turn it off and restrict management access to trusted internal IPs only.

4. Patch/upgrade path

   • The sources provided do not include any fixed firmware version for CVE-2017-14942.
   • Check Intelbras support and your vendor portal for a WRN 150 firmware update that addresses CVE-2017-14942, then upgrade if available.
   • If a fixed version exists, upgrade to the earliest safe fixed release and reboot the device after updating.

5. After mitigation/patching: reduce damage

   • Change the router admin password(s) to a strong new value.
   • Review router settings for unauthorized changes (DNS settings, port forwarding, remote management settings, admin accounts).
   • If you suspect compromise, consider broader incident steps (for example, checking connected devices and restarting the network after changes).

6. What to monitor

   • Firewall logs for repeated attempts to access router management/CGI endpoints from the internet.
   • Any unexpected configuration changes or new forwarding rules after the timeframe when the router was internet-reachable.

CISA due date

• Not available from the provided findings (this issue is not listed in the CISA KEV at the time of the provided sources).

Severity is critical (CVSS 9.8 shown in the prompt) with remote attacker capability and high impact potential.

Weakness/Mechanism: CWE-552. The attacker can read a router configuration file by making a direct request to cgi-bin/DownloadCfg/RouterCfm.cfg. The configuration content can enable authentication bypass (the prompt’s technical description notes the request includes a cookie value consistent with admin language parameters, and the bypass results from information obtained from the retrieved configuration).

Exploitation status: A public exploit is available (1 known), and press attention is described as rising. No KEV listing was found in the provided sources, so CISA catalog confirmation is not available here.

Fix availability: No patch details were found in the provided sources, so the upgrade path cannot be stated from evidence provided.