CVE-2019-13101

What it actually does

Unauthenticated direct access to wan.htm exposes WAN configuration details and permits modification of page data fields on affected D-Link DIR-600M firmware versions.

Why it matters to the business

Legacy routers remain exposed to remote information disclosure and configuration tampering, increasing risk of network disruption and data exposure for organizations still operating unpatched or end-of-life hardware.

How an attack unfolds

An attacker identifies an exposed D-Link DIR-600M device and issues an unauthenticated HTTP request to wan.htm, retrieves sensitive WAN settings, and alters data fields to impact connectivity or enable further attacks; the flaw has been weaponized in public exploits.

How to fix it

Replace end-of-life DIR-600M hardware with supported models; where replacement is delayed, restrict network access to the device management interface using firewalls or VLAN segmentation and disable WAN-side exposure.

How to confirm the fix worked

Attempt unauthenticated HTTP access to /wan.htm on the device and verify firmware versions 3.02-3.06; confirm absence of the page or enforced authentication after mitigation.

Typical attack path

1. Scan for publicly reachable D-Link DIR-600M devices
2. Issue direct unauthenticated HTTP GET to /wan.htm
3. Parse response for WAN configuration disclosure
4. Submit modified POST data to alter WAN fields

How to detect it

Inspect web server and device logs for unauthenticated requests to wan.htm; correlate with source IPs attempting direct page access outside normal management traffic.

• GET /wan.htm
• POST /wan.htm
• User-Agent strings followed by direct wan.htm access without prior login

What your security team should do

• Inventory and retire all DIR-600M devices running listed firmware versions
• Apply network segmentation to isolate legacy IoT and router hardware
• Monitor for direct HTTP requests to wan.htm in perimeter logs