CVE-2023-20250 is a stack-based buffer overflow vulnerability found in the web-based management interface of Cisco Small Business RV Series routers, specifically models RV110W, RV130, RV130W, and RV215W. The root cause is improper validation of crafted requests sent to the router's web interface, which allows an attacker with valid administrator credentials to trigger a buffer overflow condition. This overflow can be exploited to execute arbitrary code with root privileges on the affected device, potentially compromising the router's confidentiality and integrity. The vulnerability affects a wide range of firmware versions from 1.0.0.2 through 1.3.1.7, indicating a long-standing issue across multiple releases. Exploitation requires network access to the management interface and valid admin credentials, but no user interaction is needed beyond that. The CVSS v3.1 score is 6.5 (medium severity) with vector AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N, reflecting network attack vector, low attack complexity, high privileges required, no user interaction, unchanged scope, and high impact on confidentiality and integrity but no impact on availability. No public exploits or active exploitation have been reported yet. The vulnerability poses a significant risk because successful exploitation grants root-level control, enabling attackers to manipulate network traffic, exfiltrate sensitive data, or pivot to internal networks.

For European organizations, this vulnerability presents a critical risk to network security and data confidentiality. Many small and medium businesses, as well as branch offices of larger enterprises, rely on Cisco Small Business RV Series routers for secure internet connectivity and VPN services. Exploitation could lead to full compromise of these routers, allowing attackers to intercept or redirect traffic, deploy malware, or establish persistent footholds within corporate networks. Given the root-level access gained, attackers could disable security controls or create backdoors. The impact is particularly severe for organizations handling sensitive personal data under GDPR, as breaches could result in regulatory penalties and reputational damage. Additionally, critical infrastructure sectors using these routers for remote connectivity could face operational disruptions or espionage risks. The requirement for valid administrator credentials somewhat limits the attack surface but does not eliminate risk, especially if credential management practices are weak or if credentials are stolen via phishing or lateral movement.

Organizations should immediately identify and inventory affected Cisco Small Business RV Series routers and verify their firmware versions. Cisco should be consulted for available patches or firmware updates addressing CVE-2023-20250; if patches are not yet available, organizations should apply any recommended workarounds such as disabling remote web management interfaces or restricting access to trusted IP addresses only. Strong administrative credential management is critical: enforce complex passwords, implement multi-factor authentication where possible, and regularly rotate credentials. Network segmentation should isolate management interfaces from general user networks and the internet. Monitoring and logging of administrative access attempts should be enhanced to detect suspicious activity. Additionally, organizations should conduct regular vulnerability assessments and penetration tests targeting these devices to identify potential exploitation attempts. Finally, educating administrators on phishing and credential theft risks can reduce the likelihood of credential compromise.