CVE-2025-13191 is a stack-based buffer overflow vulnerability identified in the D-Link DIR-816L router, specifically in the soapcgi_main function within the /soap.cgi endpoint. This vulnerability arises from improper handling of input data, allowing an attacker to overflow the stack buffer remotely. The affected firmware version is 2_06_b09_beta, which is a beta release and no longer supported by the vendor, meaning no official patches or updates are available. The vulnerability can be exploited over the network without requiring authentication or user interaction, increasing its risk profile. The CVSS v4.0 score of 8.7 reflects a high severity, with attack vector being network-based, low attack complexity, and no privileges or user interaction needed. Successful exploitation could allow remote code execution, potentially enabling attackers to take full control of the device, disrupt network operations, or pivot into internal networks. The public disclosure of the vulnerability increases the likelihood of exploit development, although no active exploits have been reported yet. The lack of vendor support complicates remediation, making mitigation reliant on network-level controls and device replacement. The vulnerability affects only a specific outdated firmware version, limiting the scope but still posing a significant risk to organizations still operating these devices.

For European organizations, the impact of CVE-2025-13191 can be substantial, especially for those using the affected D-Link DIR-816L routers in their network infrastructure. Exploitation could lead to full device compromise, allowing attackers to intercept or manipulate network traffic, disrupt connectivity, or use the device as a foothold for further attacks within the corporate network. This could result in data breaches, service outages, and loss of control over critical network segments. Since the affected firmware is no longer supported, organizations cannot rely on vendor patches, increasing the risk of prolonged exposure. The impact is heightened for sectors with critical infrastructure or sensitive data, such as finance, healthcare, and government agencies. Additionally, remote exploitation capability means that attackers do not need physical access, broadening the attack surface. The vulnerability could also be leveraged in botnet campaigns or lateral movement within compromised networks, amplifying its threat potential.

Given the lack of vendor support and absence of official patches for the affected firmware, European organizations should prioritize the following mitigations: 1) Immediately identify and inventory all D-Link DIR-816L devices running the vulnerable firmware version. 2) Disable remote management interfaces (e.g., SOAP services) exposed to untrusted networks to reduce attack surface. 3) Segment networks to isolate vulnerable devices from critical infrastructure and sensitive data environments. 4) Replace affected devices with supported hardware running up-to-date firmware versions to eliminate the vulnerability. 5) Implement strict firewall rules to block unauthorized access to router management ports. 6) Monitor network traffic for anomalous activity indicative of exploitation attempts targeting /soap.cgi endpoints. 7) Educate IT staff about the risks of running unsupported firmware and the importance of timely device upgrades. 8) Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability once available. These measures collectively reduce the likelihood of successful exploitation and limit potential damage.