CVE-2025-70244 Overview
CVE-2025-70244 is a stack buffer overflow vulnerability [CWE-121] affecting the D-Link DIR-513 wireless router running firmware version 1.10. The flaw resides in the goform/formWlanSetup handler and is triggered through the webPage parameter. A remote, unauthenticated attacker can send a crafted HTTP request to corrupt the stack and cause a denial-of-service condition on the device.
Critical Impact
Remote unauthenticated attackers can crash the router or potentially disrupt wireless services by sending a single malformed HTTP request to the web management interface.
Affected Products
- D-Link DIR-513 hardware router
- D-Link DIR-513 firmware version 1.10
- Legacy D-Link DIR-513 deployments (end-of-life device)
Discovery Timeline
- 2026-03-10 - CVE-2025-70244 published to the National Vulnerability Database
- 2026-03-11 - Last updated in NVD database
Technical Details for CVE-2025-70244
Vulnerability Analysis
The vulnerability exists in the wireless configuration handler exposed by the embedded web server on the DIR-513. The handler at goform/formWlanSetup accepts user-supplied input through the webPage HTTP parameter without validating its length. When the input exceeds the fixed-size stack buffer used to store it, adjacent stack memory is overwritten.
This class of weakness is tracked as [CWE-121] Stack-based Buffer Overflow. Overwriting the saved return address or stack canary region causes the web server process to crash. The router's HTTP service becomes unavailable and the device may reboot or enter a degraded state.
The attack does not require authentication, user interaction, or local access. Any attacker with network reachability to the management interface can deliver the payload. Routers exposing administration on the WAN side are reachable from the public internet.
Root Cause
The root cause is the absence of bounds checking on the webPage parameter before it is copied into a stack-allocated buffer. The handler trusts the length of attacker-controlled HTTP input. Common patterns behind this defect include unsafe use of strcpy, sprintf, or memcpy in CGI-style form handlers compiled for MIPS or ARM SoCs typical of consumer routers.
Attack Vector
Exploitation is performed over the network against the router's web administration interface. An attacker submits a POST or GET request to /goform/formWlanSetup with an oversized webPage value. The malformed request reaches the vulnerable handler, the copy operation overruns the buffer, and the HTTP daemon terminates abnormally. Public technical details are available in the GitHub CVE Report.
Detection Methods for CVE-2025-70244
Indicators of Compromise
- Unexpected reboots or crashes of the DIR-513 web administration daemon
- HTTP requests targeting /goform/formWlanSetup containing unusually long webPage parameter values
- Repeated connection failures to the router management interface from external IP addresses
- Web server log entries showing truncated or malformed POST bodies prior to a service restart
Detection Strategies
- Inspect HTTP traffic to router management interfaces for parameter lengths exceeding reasonable form field sizes
- Deploy network intrusion detection signatures matching oversized webPage parameters in requests to goform endpoints
- Correlate router availability monitoring alerts with inbound HTTP traffic spikes targeting administrative ports
Monitoring Recommendations
- Log all administrative HTTP requests reaching SOHO routers via upstream firewalls or network taps
- Alert on repeated TCP resets or service restarts originating from the router management port
- Track outbound DNS or NTP behavior changes that may indicate a router was crashed or rebooted into a default state
How to Mitigate CVE-2025-70244
Immediate Actions Required
- Restrict access to the DIR-513 web administration interface to trusted internal management VLANs only
- Disable remote (WAN-side) administration on all DIR-513 devices
- Replace end-of-life DIR-513 hardware with a vendor-supported model that receives current firmware updates
- Monitor the D-Link Security Bulletin page for any vendor guidance
Patch Information
The D-Link DIR-513 is a legacy product and firmware version 1.10 is the affected baseline. No patched firmware is referenced in the published advisory data. Refer to the D-Link Product Information page and the D-Link Security Bulletin for the latest vendor status. Where no patch is available, device replacement is the recommended remediation.
Workarounds
- Place the router behind an upstream firewall that blocks unsolicited inbound traffic to TCP ports 80 and 443
- Apply ACLs to permit administrative HTTP access only from a dedicated management host
- Segment vulnerable routers off the production network until they can be decommissioned
- Disable any UPnP or port-forwarding rules that expose the management interface to the internet
# Example upstream firewall rule to block external access to router admin
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -m iprange ! --src-range 10.0.0.10-10.0.0.20 -j DROP
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -m iprange ! --src-range 10.0.0.10-10.0.0.20 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
