Hackers are taking advantage of Citrix vulnerabilities

Savvy hackers have been crawling the web in an attempt to target corporate networks impacted by the recently disclosed vulnerabilities in Citrix systems.

Earlier this month, Citrix announced it discovered multiple vulnerabilities in Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP appliance models 4000-WO, 4100-WO, 5000-WO and 5100-WO.

Shortly after the announcement was made, hackers attempted to exploit the vulnerabilities to gain access to Citrix’s application delivery controller systems. To do so, hackers exploited the vulnerabilities of CVE-2020-8195 and CVE-2020-8196 in Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP.

Johannes Ullrich, head of research at the SANS Technology Institute, used a honey pot setup to track hackers taking advantage of the Citrix vulnerabilities.

“As of today, my F5 honeypot is getting hit by attempts to exploit two of the Citrix vulnerabilities disclosed this week,” Ullrich said in a post published by the SANS Technology Institute.

“It is not clear exactly which CVE was assigned to which vulnerability, but the possible candidates are CVE-2020-8195, CVE-2020-8196,” he continued.

According to Ullrich, hackers used the vulnerabilities for arbitrary file downloads and to retrieve PCI-DSS reports from Citrix.

Citrix has since patched the vulnerabilities identified in its Citrix ADC, Citrix Gateway, and Citrix SD-WAN WANOP. This included patching CVE-2020-8195 and CVE-2020-8196 as well.

CISO Citrix CISO Fermin J. Serna explained, however: “We are limiting the public disclosure of many of the technical details of the vulnerabilities and the patches to further protect our customers. Across the industry, today’s sophisticated malicious actors are using the details and patches to reverse engineer exploits.

"As such, we are taking steps to advise and help our customers but also do what we can to shield intelligence from malicious actors.”

Several hackers have attempted to target and exploit Citrix ADC in the past few months. In March, reports revealed the state-sponsored APT41 group targeted Citrix NetScaler/ADC, Cisco routers, and Zoho ManageEngine Desktop Central products to attack 75 customers between Jan. 20 and March 11.

Finastra experienced a ransomware attack targeting its Citrix ADC servers in March, exploiting the CVE-2019-1978 vulnerability as a potential attack vector.