## U.S. Cybersecurity Agency Warns of Critical Flaw in Citrix Devices
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has issued an advisory regarding a serious security vulnerability in Citrix NetScaler Application Delivery Controller (ADC) and Gateway devices. The flaw is being actively exploited by threat actors to drop web shells on vulnerable systems.
### Citrix Devices at Risk
The security flaw affects Citrix NetScaler ADC and Gateway devices. These devices are commonly used in organizations to improve the performance and security of web applications. However, the flaw exposes them to potential attacks.
### Zero-Day Exploitation
In June 2023, threat actors discovered and exploited this vulnerability as a zero-day attack. This means that the flaw was unknown to Citrix and the cybersecurity community at the time of its exploitation. The attackers were able to drop a web shell on a critical system using this zero-day.
### Web Shells
The main concern resulting from the exploitation of this vulnerability is the installation of web shells on compromised systems. A web shell is a malicious script or program that provides unauthorized access to a compromised system. Once installed, it can be used by attackers to execute commands, steal sensitive information, or launch further attacks.
### Active Exploitation
According to the CISA advisory, there are multiple instances of threat actors actively exploiting this vulnerability to drop web shells on vulnerable Citrix devices. This means that organizations using these devices are at risk and should take immediate action to mitigate the threat.
### Recommended Actions
To protect against this vulnerability, organizations are advised to take the following actions:
– Apply the available security patches provided by Citrix.
– Implement strong access controls and limit network exposure for vulnerable Citrix devices.
– Regularly monitor the devices for any signs of compromise.
– Keep systems and software up to date with the latest security patches and updates.
The security flaw in Citrix NetScaler ADC and Gateway devices is a serious concern. The fact that it has been actively exploited by threat actors highlights the urgency for organizations to take immediate action to protect their systems. By applying the recommended actions and staying vigilant, organizations can mitigate the risk and ensure the security of their networks and data.Original Article: https://thehackernews.com/2023/07/citrix-netscaler-adc-and-gateway.html