CVE-2024-9785 Overview
CVE-2024-9785 is a buffer overflow vulnerability in the D-Link DIR-619L B1 2.06 wireless router firmware. The flaw resides in the formSetDDNS function of the /goform/formSetDDNS endpoint. Attackers can manipulate the curTime argument to trigger a buffer overflow condition remotely. The exploit details have been publicly disclosed, increasing the risk of active exploitation against exposed devices.
Critical Impact
Remote attackers with low privileges can trigger memory corruption in the router's web management interface, potentially leading to arbitrary code execution or device compromise.
Affected Products
- D-Link DIR-619L B1 router hardware revision B1
- D-Link DIR-619L Firmware version 2.06B1
- /goform/formSetDDNS web management endpoint
Discovery Timeline
- 2024-10-10 - CVE-2024-9785 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-9785
Vulnerability Analysis
The vulnerability is a classic buffer overflow classified under [CWE-120] (Buffer Copy without Checking Size of Input). The formSetDDNS handler processes Dynamic DNS (DDNS) configuration requests submitted through the router's web administration interface. When the handler processes the curTime parameter, it copies the value into a fixed-size stack buffer without validating the input length.
An authenticated attacker sending a crafted HTTP POST request to /goform/formSetDDNS can overflow the destination buffer. The overflow overwrites adjacent memory, including saved return addresses on MIPS-based router firmware. Successful exploitation can corrupt program flow, crash the HTTP daemon, or enable arbitrary code execution in the context of the router's management process.
The DIR-619L is an end-of-life consumer router, and D-Link has not indicated firmware updates for this device line. Exposed management interfaces on the WAN side substantially expand the attack surface.
Root Cause
The root cause is missing bounds checking on the curTime parameter before copying it into a fixed-size buffer. The firmware relies on unsafe string handling routines that do not validate attacker-controlled input length against the destination buffer size.
Attack Vector
Exploitation requires network access to the router's web management interface and low-privilege authentication. An attacker submits a POST request to /goform/formSetDDNS containing an oversized curTime value. The malformed request triggers the overflow during request parsing. See the GitHub IoT Vulnerability Details writeup for the disclosed proof-of-concept details.
Detection Methods for CVE-2024-9785
Indicators of Compromise
- HTTP POST requests to /goform/formSetDDNS containing abnormally long curTime parameter values.
- Repeated router reboots or HTTP daemon crashes correlated with inbound web management traffic.
- Unexpected outbound connections from the router to attacker-controlled infrastructure following management interface activity.
Detection Strategies
- Inspect web server and router syslog output for malformed requests targeting /goform/formSetDDNS endpoints.
- Deploy network intrusion detection signatures that flag oversized POST parameters directed at D-Link /goform/ URIs.
- Monitor for authentication events on router administration interfaces followed by anomalous DDNS configuration changes.
Monitoring Recommendations
- Log and alert on all HTTP requests to router administration endpoints from non-management network segments.
- Track router uptime and process crash telemetry to identify successful exploitation attempts.
- Correlate management interface traffic with network flow anomalies indicative of post-compromise activity.
How to Mitigate CVE-2024-9785
Immediate Actions Required
- Disable remote WAN-side administration on affected DIR-619L devices.
- Restrict web management interface access to trusted LAN hosts using ACLs or management VLANs.
- Replace end-of-life DIR-619L hardware with a supported router platform that receives active security updates.
Patch Information
The D-Link DIR-619L B1 is an end-of-life product. No official firmware patch has been released for CVE-2024-9785. Consult the D-Link Official Website and the VulDB Report #279937 for current advisory status.
Workarounds
- Block inbound TCP traffic to router management ports (typically 80/443) from untrusted networks at the perimeter.
- Change default administrator credentials and enforce strong authentication on the router's web interface.
- Segment the router administration plane from user networks to limit exposure to authenticated attackers.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
