CVE-2025-60691 is a critical stack-based buffer overflow vulnerability identified in the httpd binary of Linksys E1200 version 2 routers, specifically in firmware E1200_v2.0.11.001_us. The vulnerability stems from the apply_cgi and block_cgi functions, which handle CGI requests by copying user-supplied input from the "url" parameter into stack-allocated buffers using the unsafe sprintf function without any bounds checking. These buffers are allocated as single-byte variables, meaning any non-empty input causes a buffer overflow. This flaw allows remote attackers to send specially crafted HTTP requests to the router’s web management interface and overflow the stack, potentially enabling arbitrary code execution or causing a denial of service. Notably, exploitation does not require authentication or user interaction, increasing the attack surface significantly. While no public exploits have been reported yet, the vulnerability’s characteristics make it a high-risk issue, especially for devices exposed to untrusted networks. The lack of a CVSS score indicates the need for a manual severity assessment. The vulnerability affects a widely deployed consumer router model, which is often used in small offices and home environments, but could also be present in some enterprise edge networks. The exploit could allow attackers to gain control over the router, manipulate network traffic, or disrupt connectivity, posing serious security risks. No patches or firmware updates are currently linked, so mitigation relies on network segmentation, access restrictions, and monitoring for suspicious HTTP requests targeting the vulnerable CGI parameters.

For European organizations, the impact of CVE-2025-60691 can be significant. Linksys E1200 v2 routers are commonly used in small to medium-sized enterprises and home office environments, which are integral parts of broader corporate networks. Successful exploitation could lead to full compromise of the router, allowing attackers to intercept, modify, or redirect network traffic, potentially enabling man-in-the-middle attacks or lateral movement within the network. Denial of service conditions could disrupt business operations, especially for organizations relying on these devices for internet connectivity or VPN termination. The unauthenticated remote exploit vector increases the risk of widespread scanning and automated attacks, particularly if these devices are exposed to the internet. Additionally, compromised routers could be leveraged as footholds for further attacks on internal systems or as part of botnets. European entities involved in critical infrastructure, finance, or government sectors using these routers in any capacity face elevated risks due to the potential for espionage or sabotage. The lack of available patches exacerbates the threat, making timely mitigation essential to reduce exposure.

To mitigate CVE-2025-60691, European organizations should first identify any Linksys E1200 v2 routers running the vulnerable firmware version (E1200_v2.0.11.001_us). Since no official patches are currently available, immediate steps include restricting access to the router’s web management interface by implementing network segmentation and firewall rules that block HTTP access from untrusted networks, especially the internet. Disabling remote management features and changing default credentials can reduce attack surface. Monitoring network traffic for unusual HTTP requests targeting the "url" CGI parameter can help detect exploitation attempts. Organizations should consider replacing vulnerable devices with updated hardware or firmware versions once available. Employing intrusion detection systems (IDS) with signatures for buffer overflow attempts against HTTP services can provide early warnings. Regularly reviewing vendor advisories for patches and applying them promptly when released is critical. Additionally, educating users about the risks of exposing router management interfaces and enforcing strict network access controls will enhance overall security posture.