Overview
A critical stack buffer overflow vulnerability, identified as CVE-2025-60679, has been discovered in the D-Link DIR-816A2 router. This vulnerability affects the firmware version DIR-816A2_FWv1.10CNB05_R1B011D88210.img and resides within the upload.cgi module, which handles firmware version information. Successfully exploiting this vulnerability could allow a remote attacker to execute arbitrary code on the affected device.
Technical Details
The vulnerability stems from insufficient input validation within the upload.cgi module when processing firmware version information. Specifically, the content of /proc/version is read into a 512-byte buffer. This content is then concatenated using sprintf() into another 512-byte buffer, which already contains a 29-byte constant string. If the data read from /proc/version exceeds 481 bytes, a stack buffer overflow occurs.
An attacker who can control the content of /proc/version can leverage this overflow to overwrite adjacent memory on the stack, potentially injecting and executing malicious code. This control can be achieved through various means, depending on the router’s configuration and existing vulnerabilities.
CVSS Analysis
As of the publication of this article, the CVSS score for CVE-2025-60679 is currently listed as N/A. A full risk assessment, including CVSS score, is pending. However, given the potential for arbitrary code execution, it is anticipated that the severity will be rated as high or critical once CVSS score is available.
Possible Impact
The exploitation of CVE-2025-60679 can have significant consequences:
- Arbitrary Code Execution: An attacker can potentially execute arbitrary code on the router, gaining complete control of the device.
- Device Compromise: A compromised router can be used as a pivot point to attack other devices on the network.
- Data Theft: Sensitive data transmitted through the router could be intercepted and stolen.
- Denial of Service: The router could be rendered unusable, disrupting network connectivity.
Mitigation and Patch Steps
The most effective mitigation is to update the router’s firmware to a patched version that addresses this vulnerability. D-Link has been notified, and users should:
- Check for Firmware Updates: Regularly check the D-Link security bulletin and the D-Link support website for firmware updates specifically addressing CVE-2025-60679.
- Apply Updates Immediately: If a patched firmware version is available, apply the update as soon as possible.
- Temporary Mitigation (If no patch available): If a patch is not yet available, consider limiting access to the router’s web interface from the external network. This won’t fully mitigate the risk, but it can reduce the attack surface.
