Multiple Citrix Products CVE-2019-19781 Remote Code Execution Vulnerability

Description

Multiple Citrix Products are prone to a remote code-execution vulnerability. Successfully exploiting this issue will allow attackers to execute arbitrary code within the context of the application.

Technologies Affected

• Citrix NetScaler Gateway 10.5
• Citrix NetScaler Gateway 11.1
• Citrix NetScaler Gateway 12.0
• Citrix NetScaler Gateway 12.1
• Citrix NetScaler Gateway 13.0
• Citrix Netscaler Application Delivery Controller 10.5
• Citrix Netscaler Application Delivery Controller 11.1
• Citrix Netscaler Application Delivery Controller 12.0
• Citrix Netscaler Application Delivery Controller 12.1
• Citrix Netscaler Application Delivery Controller 13.0

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits

Implement multiple redundant layers of security.
Various memory-protection schemes (such as non-executable and randomly mapped memory segments) may hinder an attacker’s ability to exploit this vulnerability to execute arbitrary code.

Updates are available. Please see the references or vendor advisory for more information.