Last week, Citrix addressed the actively exploited CVE-2019-19781 flaw in Citrix Application Delivery Controller (ADC), Citrix Gateway, and Citrix SD-WAN WANOP appliances.
Researchers at MDSsec published technical details of the vulnerability along with a video that shows the exploit they have developed, but they decided to not release it to avoid miscreants use it in the wild.
It has been estimated that 80,000 companies in 158 countries are potentially at risk, most of them in the U.S. (38%), followed by the UK, Germany, the Netherlands, and Australia.
The CVE-2019-19781 vulnerability was discovered by Mikhail Klyuchnikov from Positive Technologies.
The flaw affects ADC and Gateway versions 10.5, 11.1, 12.0, 12.1, and 13.0, as well as SD-WAN WANOP versions 10.2.6 and 11.0.3.
Citrix released on Friday, the final set of permanent fixes for the
“As with the permanent fixes made available for Citrix ADC and Citrix Gateway versions 11.1, 12.0, 12.1, 13.0, and Citrix SD-WAN 4000-WO, 5000-WO, 4100-WO, and 5100-WO earlier this week, these fixes are available to all customers regardless of whether they have an active maintenance contract with Citrix,” reads the post published by Fermin J. Serna, Chief Information Security Officer at Citrix.
Security experts are monitoring a spike in the number of attacks against Citrix servers after that researchers announced the availability online of proof-of-concept exploits for the CVE-2019-19781 flaw in Citrix NetScaler ADC and Citrix NetScaler Gateway servers.
Researchers from FireEye noticed that one of the threat actors involved in the attacks is patching the vulnerable Citrix servers, installing their own
The NOTROBIN backdoor was designed to prevent subsequent exploitation of the flaw on Citrix servers and also to establish backdoor access, a circumstance that suggests that attackers are preparing future attacks.
It is easy to predict that threat