Threat Advisory - DTLS Amplification Distributed Denial of Service Attack on Citrix ADC and Citrix Gateway

Threat Information Citrix is aware of a DDoS attack pattern impacting Citrix ADCand Citrix Gateway. As part of this attack, an attacker or bots can overwhelm the Citrix ADCDTLS network throughput, potentially leading to outbound bandwidth exhaustion. The effect of this attack appears to be more...

VDA launch failure via Workspace and browser with error "VDA refused connection"

While launching the applications after successful gateway authentication from the browser and Citrix workspace app. users get error "Gateway authentication failed because VDA refused connection "...

VDA Showing Unregistered in Studio due to error "Test call from Cloud Connector to VDA failed."

VDAs are showing as unregistered in the Studio Console, VDA event log show below error: Test call from Cloud Connector to VDA failed...

Event: 1050 Connection validation failed on domain for user for reason 'Deny'

SSL Certificate handshake is not successful for ICA sessions since the VDA's are not enabled for SSL communications. Mismatch of License edition configured on Studio...

User session fails to launch session Received an invalid packet during its ?? handshake phase

In System Event log on the VDA a TDICA event 1019 appears. "The Citrix TDICA Transport Driver connection from xxx.xxx.xxx.xxx: to port 443received an invalid packet during its ?? handshake phase" There is however no issue launching the session and no disconnection takes place. In this scenario th...

NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-19489 and CVE-2026-19490

Multiple vulnerabilities have been discovered in NetScaler ADC formerly Citrix ADC and NetScaler Gateway formerly Citrix Gateway. Refer below for further details. The information on this page is being provided to you on an "AS IS" and "AS-AVAILABLE" basis. The issues described on this page may or...

The Server (Unknown) is Not Trusted for ICA Connections

When trying to launch applications from a published XenApp server desktop, the following error message appears: “Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. The server Unknown is not trusted for ICA...

SAML Intermittence on Citrix Gateway: Internal server error 43524

Users may experience intermittent issues during the SAML configuration process on Citrix Gateway. This can result in unpredictable behavior, with some users successfully accessing the SAML login while others encountering an "Internal server error 43524" message...

NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-8451, CVE-2026-8452, CVE-2026-8655, CVE-2026-10816, CVE-2026-10817, and CVE-2026-13474

Severity - High Description of Problem Multiple vulnerabilities have been discovered in NetScaler ADC formerly Citrix ADC and NetScaler Gateway formerly Citrix Gateway. Refer below for further details. Affected Versions: The following supported versions of NetScaler ADC and NetScaler Gateway are...

CVE-2014-3566 - Citrix Security Advisory for SSLv3 Protocol Flaw

Description of Problem The recently disclosed protocol flaw in SSLv3, referred to as CVE-2014-3566 or POODLE, could expose some deployments that support SSLv3 to a risk of an active Man in the Middle MITM attack. A successful attack could lead to the disclosure of the information that is being se...

How to Collect a Citrix Diagnostic Facility (CDF) Trace at System Startup

The CDFControl utility is an event tracing controller or consumer for capturing Citrix Diagnostic Facility CDF trace messages displayed from various Citrix tracing providers. It is made to troubleshoot complex Citrix related issues, parse filter support, and collect performance data. To download...

PVS boot time message "Attempting to set IP address on Boot NIC.......complete after 51s."

Target devices show a boot time message "Attempting to set IP address on Boot NIC.......complete after 51s." This message was not observed in earlier versions of PVS target device software like PVS 1912...

PVS target BSOD on CVhdMp.sys

The VMWare based PVS target boots from the vdisk to message "Attempting to set IP address on Boot NIC..." and 60 seconds later BSODs. The vdisk will boot successfully on the master target device, but not on other devices...

VDA Registration Step by Step and Troubleshoot common VDA Registration Failures

This article explains step by step process of VDA registration and troubleshoot common VDA registration failure issues...

Citrix Security Advisory for CVE-2021-44228, CVE-2021-45046, CVE-2021-45105 and CVE-2021-44832.

Citrix is aware offourvulnerabilitiesaffectingApache Log4j2, threeof whichmayallowan attackertoexecute arbitrary code. Thesethreevulnerabilitieshavebeen given the followingidentifiers: CVE-2021-44228 CVE-2021-45046 CVE-2021-44832 Thefourthvulnerabilitymay allowan attackertocause a denial of...

CVE-2019-19781 - Vulnerability in Citrix Application Delivery Controller, Citrix Gateway, and Citrix SD-WAN WANOP appliance

Description of Problem A vulnerability has been identified in Citrix Application Delivery Controller ADC formerly known as NetScaler ADC and Citrix Gateway formerly known as NetScaler Gateway that, if exploited, could allow an unauthenticated attacker to perform arbitrary code execution. The scop...

Citrix Application Delivery Controller, Citrix Gateway, and Citrix SD-WAN WANOP Edition appliance Security Update

Vulnerabilities have been discovered in Citrix ADCformerlyknown asNetScaler ADC,Citrix Gateway formerlyknown asNetScaler Gateway,and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO.These vulnerabilities,if exploited,could result in the following security issues: CVE-ID|...

Citrix Hypervisor Security Update

Description of Problem Two security issues have been identified in Citrix Hypervisor formerly Citrix XenServer that may allow privileged code in a guest VM to cause the host to crash or become unresponsive. These issues affect all currently supported versions of Citrix Hypervisor up to and...

ADC SAML Error : “Malformed Assertion sent to NetScaler; Please contact your administrator”

End user getting the error message : “Malformed Assertion sent to NetScaler; Please contact your administrator” after authenticating at IDP ADFS v3...

Wfica32.exe crashes when attempting to launch new session

Wfica32.exe crashes when attempting to launch Citrix ICA session from client side. From the client's Windows application logs, the following errors are noticed. ・Application Error with Event ID 1000 which indicates the faulting application name is WFICA32.EXE. ・Application Error with Event ID 1...

Citrix Workspace App Security Update

Description of Problem A vulnerability has been identified that could result in a local user escalating their privilege level to SYSTEM on the computer running Citrix Workspace app for Windows. The vulnerability has the following identifier: CVE ID| Description| Vulnerability Type| Pre-conditions...

Citrix Federated Authentication Service (FAS) Security Update

An issue has been identified in Citrix Federated Authentication Service FAS which causes deployments that have been configured to store a registration authority certificate's private key in a Trusted Platform Module TPM to incorrectly store that key in the Microsoft Software Key Storage Provider...

Citrix ShareFile storage zones controller security update

Description of Problem A security issue has been identified in the Citrix ShareFile storage zones controller which, if exploited, would allow an unauthenticated attacker to remotely compromise the storage zones controller. The issue has been given the following identifier: CVE-ID | Description |...

iOS Workspace Error "Http/1.1 Internal Server Error 43549" via Gateway nFactor Authentication

Workspace for iOS shows "Http/1.1 Internal Server Error 43549" after successful authentication via NetScaler Gateway. Workspace for Windows works fine. AAA nFactorauthentication profile is configured in NetScaler Gateway...

Workspace error 2306 happen when ICA file located in path which contains Chinese characters

Workspace error 2306 happen when ICA file located in path which contains Chinese character. Error message "Could not find the file named "C:??\.ica. Please check your installation , or contact your administrator."...

Citrix Hypervisor Security Update

Description of Problem A security issue has been identified that may allow privileged code running in a guest VM to compromise the host. This issue is limited to only those guest VMs where the host administrator has explicitly assigned a PCI passthrough device to the guest VM. The issue has the...

Citrix VDA Cleanup Utility Tool

Note: Please note: You can download the required file from the Citrix downloads website by visiting the following link:https://www.citrix.com/downloads/citrix-tools All references to VDA in this article are to the Windows version of VDA. Citrix recommends that you use the built-in uninstaller to...

Unable to launch ICA session due to wfica32.exe signature validation failure

After upgrading Citrix Workspace App to 2203 CU2 and 2210.5 and above in customer's client machine, ICA session became unable to launch. Specifically, ICA file can be downloaded but wfica32.exe never starts. The issue doesn't occur in the same client machine with Citrix Workspace App for Windows...

Citrix ADC and Citrix Gateway Security Bulletin for CVE-2022-27507 and CVE-2022-27508

Vulnerabilities have been discovered in Citrix ADC and Citrix Gateway that, if exploited, could result in a denial of service. These vulnerabilities have the following identifiers: CVE-ID| Description| CWE| Pre-conditions ---|---|---|--- CVE-2022-27507| Authenticated denial of service| CWE-400:...

Citrix ADC and Citrix Gateway Security Bulletin for CVE-2023-24487, CVE-2023-24488

Vulnerabilities have been discovered in Citrix ADC and Citrix Gateway listed below, that, if exploited, could result in the following security issues: Impacted Products, Versions and Components The following supported versions of Citrix ADC and Citrix Gateway are affected by this vulnerability:...

NetScaler shows an error stating "String length exceeds maximum [passplain, 31]"

When trying to update an existing certificate file with a new certificate file, upon clicking 'Ok', you see the following error appear: "String length exceeds maximum passplain, 31" The attempt to save the changes made fail because of the error which appears...

Citrix Hypervisor Security Update

Several security issues have been identified that affect Citrix Hypervisor: Two issues, each of which may each allow privileged code in a guest VM to cause the host to crash or become unresponsive. These two issues only affect systems where the malicious guest VM has a physical PCI device passed...

Citrix Hypervisor Security Update

Description of Problem A security issue has been identified that may allow privileged code running in a guest VM to which a PCI passthrough device has been allocated to cause other VMs with PCI passthrough devices to fail to boot, crash or become unresponsive. This only applies to guest VMs where...

Your corporate Citrix environment is currently unsupported alert shown even no expired license files

The alert "Citrix Virtual Apps and Desktops Warning: Your corporate Citrix environment is currently unsupported. Please contact your IT department to resolve." is shown when starting the session. No expired license file is stored on the license server...

Graphical Issues with Citrix Workspace App 2503 and Intel GPUs

Customers using the Citrix Workspace App for Windows version 2503 or later on Windows endpoint devices, like the Microsoft Surface Pro laptops equipped with specific Intel GPUs using older Intel drivers, may encounter graphical anomalies. These issues can manifest as visual artefacts or black box...

Citrix Virtual Apps and Desktops Security Update

A vulnerability has been identified in Citrix Virtual Apps and Desktops that could, if exploited, allow a user of a Windows VDA that has either Citrix Profile Management or Citrix Profile Management WMI Plugin installed to escalate their privilege level on that Windows VDA to SYSTEM. This...

How to enable Teams Optimization with Microsoft's new VDI Optimization engine - SlimCore

Microsoft has released a new VDI solution for Teams. This is a how-to guide detailing the steps necessary to enable the SlimCore Optimization for Teams. We hope this guide will ease your effort to enable the new solution in your environment. If you have further feedback that you want to share wit...

Netscaler Notice of Status Change Announcement for Classic Policy Based Features and Functionalities

Citrix Systems, Inc. announces a Notice of Status Change NSC for Citrix ADC Classic policy-based features and functionalities. The dates and milestones provided are in accordance with stated End of Life/End of Support policies for Citrix Systems, Inc. Citrix ADC Features & Functionalities Affecte...

Citrix Virtual Apps and Desktops Security Update

Description of Problem Vulnerabilities havebeen identified in CitrixVirtual Apps and Desktopsthat could, if exploited,result in: An authenticateduserof amulti-sessionWindowsVDA, who has been granted permission to write to c:\ root directory, being able toescalatetheir privilege levelon that...

Updating MCS catalog fails with error FailedToUnregisterMasterImageFromMdm

Error updating an MCS catalog in Citrix DAAS Action Name: MCCreateMachineCatalogInitialzation Exception: StudioErrorId : ProvisioningTaskError ErrorCategory : NotSpecified TaskState : FailedToUnregisterMasterImageFromMdm TaskStateInformation : Terminated ErrorId :...

Citrix Hypervisor Security Update

Description of Problem Several security issues have been identified that, collectively, may allow privileged code running in a guest VM to compromise the host or cause a denial of service. These vulnerabilities have the following identifiers: CVE ID| Description| Vulnerability Type| Pre-condition...

Citrix ADC and Citrix Gateway Security Bulletin for CVE-2022-27509

A vulnerability has been discovered in Citrix ADC and Citrix Gateway which enables an attacker to create a specially crafted URL that redirects to a malicious website. This vulnerability has the following identifier: CVE-ID| Description| CWE| Pre-conditions ---|---|---|--- CVE-2022-27509|...

Citrix ShareFile storage zones controller security update

Anissuehasbeen identified intheCTX269106mitigation toolforCitrix ShareFilestorage zones controllerwhichcausestheShareFilefile encryptionoptiontobecomedisabledifit hadpreviouslybeenenabled. Customers areonlyaffected by this issue if theypreviouslyselected “Enable Encryption”in the ShareFilestorage...

Citrix Cloud Intermittent loss of connectivity to On-Prem AD

When attempting to run MCS Process - Ran into issues contacting the On-Prem Active Directory Citrix.CloudServices.ADAgent EventID 10102 Errors: Message=Unable to connect to the forest associated with domain "DOMAINNAME.local"...

Citrix Application Delivery Controller, Citrix Gateway, and Citrix SD-WAN WANOP Edition appliance Security Update

Multiple vulnerabilities have been discovered in Citrix ADCformerlyknown asNetScaler ADCandCitrix Gateway formerlyknown asNetScaler Gateway,and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO.These vulnerabilities,if exploited,could result in the following security issue...

How to Deploy Citrix Gateway Plug-in and Endpoint Analysis Installer Packages for Windows by Using Active Directory Group Policy

This article contains information about deploying the Citrix Gateway Plug-in and Endpoint Analysis EPA Microsoft Installer MSI packages for Windows by using an Active Directory Group Policy. If users do not have administrative privileges to install the Citrix Gateway Plug-in and EPA Plug-in on th...

XenServer and Citrix Hypervisor Security Update for CVE-2023-46842, CVE-2024-2201 and CVE-2024-31142

Description of Problem Two issues have been identified that affect XenServer and Citrix Hypervisor; each issue may allow malicious unprivileged code in a guest VM to infer the contents of memory belonging to its own or other VMs on the same host. These issues have the following identifiers:...

Error "Socket Error 10054" When Launching Virtual Desktop

Error "Socket Error 10054" when launching Virtual Desktop...

Citrix Security Advisory for TCP/IP Reassembly Resource Exhaustion

Description of Problem Several vulnerabilities in TCP/IP reassembly commonly known as SegmentSmack and FragmentSmack have recently been disclosed. SegmentSmack is CVE-2018-5390 for Linux and CVE-2018-6922 for FreeBSD. FragmentSmack is CVE-2018-5391 for Linux and CVE-2018-6923 for FreeBSD. These...

Cloud Software Group Security Advisory for CVE-2024-6387

Advisory for 3rd party CVE-2024-6387 Cloud Software Group is aware of the vulnerability CVE-2024-6387 impacting OpenSSH. Qualys has discovered a remote unauthenticated code execution vulnerability in OpenSSH’s server sshd in glibc-based Linux systems. Because this vulnerability is a regression of...