CVE-2024-9914 Overview
CVE-2024-9914 is a buffer overflow vulnerability affecting the D-Link DIR-619L B1 router running firmware version 2.06. The flaw resides in the formSetWizardSelectMode function accessed through the /goform/formSetWizardSelectMode endpoint. Attackers can trigger the overflow by manipulating the curTime argument. The vulnerability is exploitable over the network and the exploit has been publicly disclosed. This weakness is classified under CWE-120, covering buffer copy operations without input size checks.
Critical Impact
Remote attackers can trigger a buffer overflow in the DIR-619L web management interface, potentially leading to arbitrary code execution or device compromise on affected routers.
Affected Products
- D-Link DIR-619L B1 hardware revision
- D-Link DIR-619L firmware version 2.06b1
- Devices exposing /goform/formSetWizardSelectMode on the management interface
Discovery Timeline
- 2024-10-13 - CVE-2024-9914 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-9914
Vulnerability Analysis
The vulnerability exists in the formSetWizardSelectMode handler within the DIR-619L web management application. This handler processes wizard configuration requests submitted to /goform/formSetWizardSelectMode. The curTime request parameter is copied into a fixed-size stack or heap buffer without proper bounds validation.
An attacker who submits an oversized curTime value overruns the destination buffer. This overflow corrupts adjacent memory, including saved return addresses on the stack. On MIPS-based D-Link routers, such conditions typically allow control-flow hijacking through return-oriented programming. The D-Link DIR-619L B1 is an end-of-life product, and no vendor patch is expected.
Root Cause
The root cause is the absence of length validation on the curTime parameter before it is copied into a fixed-size buffer. The developers used an unbounded copy routine such as strcpy or sprintf rather than a length-limited alternative. This coding pattern is characteristic of CWE-120 buffer copy weaknesses.
Attack Vector
Exploitation requires network access to the router's HTTP management interface and low-privileged authenticated access. An attacker submits a crafted POST request to /goform/formSetWizardSelectMode containing an oversized curTime value. When the management interface is exposed to the WAN or an attacker resides on the LAN, no additional prerequisites are required.
The vulnerability manifests when the vulnerable handler copies the attacker-controlled string into the undersized destination buffer. See the GitHub vulnerability report for the technical proof-of-concept details.
Detection Methods for CVE-2024-9914
Indicators of Compromise
- HTTP POST requests to /goform/formSetWizardSelectMode containing abnormally long curTime parameter values
- Router web service crashes, reboots, or unexpected restarts of the httpd process
- Unusual outbound connections originating from the router management plane after suspicious requests
Detection Strategies
- Inspect network traffic for POST requests to /goform/formSetWizardSelectMode where the curTime field exceeds expected length or contains non-printable byte sequences
- Deploy IDS/IPS signatures that match oversized parameter values on D-Link /goform/ endpoints
- Correlate router syslog entries with web request logs to identify crash-and-reconnect patterns following management interface access
Monitoring Recommendations
- Aggregate router logs into a central SIEM to identify management interface anomalies
- Alert on any WAN-side access attempts to router administrative endpoints
- Monitor DHCP and ARP tables for unexpected changes that may indicate post-exploitation activity on the LAN
How to Mitigate CVE-2024-9914
Immediate Actions Required
- Disable remote (WAN-side) HTTP management on affected DIR-619L devices immediately
- Restrict LAN-side management access to a dedicated administrative VLAN or trusted host list
- Replace end-of-life DIR-619L B1 routers with a currently supported model, as D-Link has designated this device end-of-life
Patch Information
No vendor patch is available. The D-Link DIR-619L B1 product line has reached end-of-life and end-of-support status. Refer to the D-Link official website for product support status. Migrating to a supported router is the definitive remediation.
Workarounds
- Block external access to TCP port 80 and TCP port 443 on the router's WAN interface
- Change the default administrator password and use a strong, unique credential to limit low-privileged exploitation paths
- Segment the router's management network from user and guest networks
- Consider placing the device behind a properly configured upstream firewall until it can be replaced
# Example: block inbound WAN access to router management ports on an upstream firewall
iptables -A FORWARD -i wan0 -p tcp --dport 80 -j DROP
iptables -A FORWARD -i wan0 -p tcp --dport 443 -j DROP
iptables -A FORWARD -i wan0 -p tcp --dport 8080 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
