Numerous working exploits for the Citrix ADC (NetScaler) CVE-2019-19781 vulnerability are finally here and have been publicly posted in numerous locations. There is no patch available for this vulnerability, but Citrix has provided mitigations, which should be applied now! If successfully exploited, this vulnerability allows unauthenticated users to utilize directory traversal to perform arbitrary code execution. The public proof-of-concept (PoC) exploits that have been released allow attackers to easily create reverse shells back to their machines and execute commands.
Source: https://www.bleepingcomputer.com/news/security/citrix-adc-cve-2019-19781-exploits-released-fix-now/