This indicates an attack attempt to exploit a Directory Traversal Vulnerability in Citrix Application Delivery Controller.
The vulnerability is due to insufficient sanitizing of user supplied inputs. A remote attacker may be able to exploit this to execute arbitrary commands within the context of the application, via a crafted HTTP request.
Citrix ADC and Citrix Gateway version 13.0 all supported builds
Citrix ADC and NetScaler Gateway version 12.1 all supported builds
Citrix ADC and NetScaler Gateway version 12.0 all supported builds
Citrix ADC and NetScaler Gateway version 11.1 all supported builds
Citrix NetScaler ADC and NetScaler Gateway version 10.5 all supported builds
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.