==================================================================== CERT-Renater Note d'Information No. 2020/VULN373 _____________________________________________________________________ DATE : 08/07/2020 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running Citrix ADC, Citrix Gateway, versions prior to 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.14, 10.5-70.18, Citrix SDWAN WAN-OP versions prior to 11.1.1a, 11.0.3d, 10.2.7, Citrix Gateway Plug-in for Linux versions prior to 1.0.0.137. ===================================================================== https://support.citrix.com/article/CTX276688 _____________________________________________________________________ CTX276688 Citrix Application Delivery Controller, Citrix Gateway, and Citrix SD-WAN WANOP appliance Security Update Security Bulletin | Critical | Created: 07 Jul 2020 | Modified: 07 Jul 2020 Applicable Products Citrix ADC Citrix Gateway Citrix SD-WAN WANOP Description of Problem Multiple vulnerabilities have been discovered in Citrix ADC (formerly known as NetScaler ADC), Citrix Gateway (formerly known as NetScaler Gateway) and Citrix SD-WAN WANOP appliance models 4000-WO, 4100-WO, 5000-WO, and 5100-WO. These vulnerabilities, if exploited, could result in a number of security issues including: Attacks that are limited to the management interface System compromise by an unauthenticated user on the management network. System compromise through Cross Site Scripting (XSS) on the management interface Creation of a download link for the device which, if downloaded and then executed by an unauthenticated user on the management network, may result in the compromise of their local computer. Mitigating Factors: Customers who have configured their systems in accordance with Citrix recommendations in https://docs.citrix.com/en-us/citrix-adc/citrix-adc-secure-deployment/secure-deployment-guide.html have significantly reduced their risk from attacks to the management interface. Attacks that are applicable to a Virtual IP (VIP) Denial of service against either the Gateway or Authentication virtual servers by an unauthenticated user (the load balancing virtual server is unaffected). Remote port scanning of the internal network by an authenticated Citrix Gateway user. Attackers can only discern whether a TLS connection is possible with the port and cannot communicate further with the end devices. Mitigating Factors: Customers who have not enabled either the Gateway or Authentication virtual servers are not at risk from attacks that are applicable to those servers. Other virtual servers e.g. load balancing and content switching virtual servers are not affected by these issues. In addition, a vulnerability has been found in Citrix Gateway Plug-in for Linux that would allow a local logged-on user of a Linux system with that plug-in installed to elevate their privileges to an administrator account on that computer. The issues have the following identifiers:  CVE ID Vulnerability Type Affected Products Attacker privileges Pre-conditions CVE-2019-18177 Information disclosure Citrix ADC, Citrix Gateway Authenticated VPN user Requires a configured SSL VPN endpoint CVE-2020-8187 Denial of service Citrix ADC, Citrix Gateway 12.0 and 11.1 only Unauthenticated remote user Requires a configured SSL VPN or AAA endpoint CVE-2020-8190 Local elevation of privileges Citrix ADC, Citrix Gateway Authenticated user on the NSIP This issue cannot be exploited directly. An attacker must first obtain nobody privileges using another exploit CVE-2020-8191 Reflected Cross Site Scripting (XSS) Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Unauthenticated remote user Requires a victim who must open an attacker-controlled link in the browser whilst being on a network with connectivity to the NSIP CVE-2020-8193 Authorization bypass Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Unauthenticated user with access to the NSIP Attacker must be able to access the NSIP CVE-2020-8194 Code Injection Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Unauthenticated remote user Requires a victim who must download and execute a malicious binary from the NSIP CVE-2020-8195 Information disclosure Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Authenticated user on the NSIP - CVE-2020-8196 Information disclosure Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Authenticated user on the NSIP - CVE-2020-8197 Elevation of privileges Citrix ADC, Citrix Gateway Authenticated user on the NSIP - CVE-2020-8198 Stored Cross Site Scripting (XSS) Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP Unauthenticated remote user Requires a victim who must be logged in as an administrator (nsroot) on the NSIP CVE-2020-8199 Local elevation of privileges Citrix Gateway Plug-in for Linux Local user on the Linux computer running Citrix Gateway Plug-in A pre-installed version of Citrix Gateway Plug-in for Linux must be running The following versions of Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP remediate the vulnerabilities:  Citrix ADC and Citrix Gateway 13.0-58.30 and later releases Citrix ADC and NetScaler Gateway 12.1-57.18 and later 12.1 releases Citrix ADC and NetScaler Gateway 12.0-63.21 and later 12.0 releases Citrix ADC and NetScaler Gateway 11.1-64.14 and later 11.1 releases NetScaler ADC and NetScaler Gateway 10.5-70.18 and later 10.5 releases Citrix SD-WAN WANOP 11.1.1a and later releases Citrix SD-WAN WANOP 11.0.3d and later 11.0 releases Citrix SD-WAN WANOP 10.2.7 and later 10.2 releases Citrix Gateway Plug-in for Linux 1.0.0.137 and later versions What Customers Should Do Fixed builds have been released for all supported versions of Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP. Citrix strongly recommends that customers immediately install these updates. The latest builds can be downloaded from https://www.citrix.com/downloads/citrix-adc/ and https://www.citrix.com/downloads/citrix-gateway/ and https://www.citrix.com/downloads/citrix-sd-wan/. Customers who are unable to immediately update to the latest version are advised ensure access to the management interface is restricted. Please see https://docs.citrix.com/en-us/citrix-adc/citrix-adc-secure-deployment/secure-deployment-guide.html for more information. Users with Citrix Gateway Plug-in for Linux should log-in to an updated version of Citrix Gateway and select ‘Network VPN mode’. Citrix Gateway will then prompt the user to update. Customers with Citrix-managed Citrix Gateway service do not need to take any action. Acknowledgements Citrix thanks Laurent Geyer of Akamai, Muris Kurgas of Digital 14 (Xen1thLabs), Maarten Boone (@staatsgeheim), Donny Maasland (@donnymaasland), Albert Shi of Univision Network (Shanghai) Co., Ltd and Viktor Dragomiretskyy for working with us to protect Citrix customers. What Citrix Is Doing Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at http://support.citrix.com/. Obtaining Support on This Issue If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at https://www.citrix.com/support/open-a-support-case.html. Reporting Security Vulnerabilities Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to Citrix, please visit the Citrix Trust Center at https://www.citrix.com/about/trust-center/vulnerability-process.html. Changelog Date Change 2020-07-07 Initial publication ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23/25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email:cert@support.renater.fr + =========================================================