A critical security vulnerability has been identified in widely used networking products, posing an urgent risk to organizations globally. This zero-day exploit, designated as CVE-2023-4966, affects specific versions of Citrix NetScaler ADC and Citrix NetScaler Gateway.
The vulnerability is an injection vulnerability that could allow an unauthenticated attacker to perform sensitive information disclosure. Even more concerning, researchers and security firms have observed this exploit being actively used in the wild, targeting vulnerable systems. This means attackers are already attempting to compromise systems before patches are applied.
The potential impact is severe. Successful exploitation can lead to remote code execution under certain conditions, granting attackers significant control over affected appliances and potentially the connected network. Given the critical role these devices play in providing secure access, the implications for data breaches and network disruption are substantial.
Organizations using the affected products are strongly advised to take immediate action. Citrix has released security updates that address this flaw. Applying the latest patches is the most critical step to mitigate the risk. Delaying patching leaves systems exposed to potential compromise by attackers already leveraging the zero-day exploit. It is imperative to identify all affected instances and apply the necessary updates immediately to secure your infrastructure against this urgent threat. Staying vigilant and applying security updates promptly is essential in the face of evolving cyber threats like this one.
Source: https://go.theregister.com/feed/www.theregister.com/2025/06/25/citrix_netscaler_critical_bug_exploited/
