CVE-2025-60679 is a stack-based buffer overflow vulnerability identified in the D-Link DIR-816A2 router firmware version DIR-816A2_FWv1.10CNB05_R1B011D88210.img, specifically within the upload.cgi module responsible for handling firmware version information. The vulnerability stems from unsafe handling of the /proc/version file content, which is read into a 512-byte buffer and then concatenated using sprintf() into another 512-byte buffer that already contains a 29-byte constant string. Because sprintf() does not perform bounds checking, if the /proc/version content exceeds 481 bytes, it causes a stack buffer overflow (CWE-121). This overflow can overwrite the stack, potentially allowing an attacker to execute arbitrary code with the privileges of the process running upload.cgi. Exploitation requires the attacker to control the content of /proc/version, which may be possible in certain attack scenarios such as local privilege escalation or through other chained vulnerabilities. The vulnerability does not require user interaction and only requires low privileges (PR:L) to exploit, making it a significant risk. The CVSS v3.1 base score of 8.8 reflects a high severity with network attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. No public exploits or patches are currently known, but the vulnerability has been officially published and reserved since September 2025. This vulnerability is critical for devices running the affected firmware and could lead to full device compromise, enabling attackers to manipulate network traffic, disrupt services, or pivot into internal networks.

For European organizations, the exploitation of CVE-2025-60679 could lead to complete compromise of affected D-Link DIR-816A2 routers, resulting in unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network availability. This is particularly concerning for enterprises relying on these routers for critical connectivity or in industrial environments where network integrity is paramount. The ability to execute arbitrary code on the device could allow attackers to install persistent malware, create backdoors, or launch further attacks against connected systems. Given the high CVSS score and the network-based attack vector, the threat could propagate rapidly if exploited in large-scale deployments. The lack of user interaction and low privilege requirements increase the likelihood of exploitation in environments where the attacker can influence or control the /proc/version content, such as compromised internal hosts or through chained vulnerabilities. This vulnerability also poses risks to managed service providers and ISPs using these routers in their infrastructure, potentially affecting multiple European customers. The overall impact includes loss of confidentiality, integrity, and availability of network communications and services.

1. Immediately restrict access to the upload.cgi module by implementing network segmentation and firewall rules to limit exposure only to trusted management networks. 2. Monitor router logs and network traffic for unusual activity indicative of exploitation attempts, such as unexpected process executions or anomalous firmware version queries. 3. Disable or restrict any functionality that allows modification or control of /proc/version content unless absolutely necessary, and audit systems that could influence this file. 4. Deploy intrusion detection/prevention systems (IDS/IPS) with signatures targeting buffer overflow attempts on the upload.cgi endpoint. 5. Engage with D-Link support to obtain firmware updates or patches addressing this vulnerability as soon as they become available and prioritize their deployment. 6. For environments where patching is delayed, consider temporary mitigations such as disabling remote management interfaces or using VPNs to secure administrative access. 7. Conduct internal vulnerability assessments to identify all devices running the affected firmware version and replace or upgrade them if possible. 8. Educate network administrators about this vulnerability and ensure incident response plans include steps for potential exploitation scenarios involving router compromise.