Two vulnerabilities have been discovered in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway). Refer below for further details.
NetScaler are affected is RDP-Proxy Feature is enabled and/or Kerberos Constrained Delegation is configured!
Affected Versions
The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities:
NetScaler ADC and NetScaler Gateway 14.1 BEFORE 14.1-29.72
NetScaler ADC and NetScaler Gateway 13.1 BEFORE 13.1-55.34
NetScaler ADC 13.1-FIPS BEFORE 13.1-37.207
NetScaler ADC 12.1-FIPS BEFORE 12.1-55.321
NetScaler ADC 12.1-NDcPP BEFORE 12.1-55.321
Note: NetScaler ADC and NetScaler Gateway versions 12.1 and 13.0 are now End Of Life (EOL) and are vulnerable. Customers are recommended to upgrade their appliances to one of the supported versions that address the vulnerabilities.
This bulletin only applies to customer-managed NetScaler ADC and NetScaler Gateway. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.
Summary
NetScaler ADC and NetScaler Gateway contain the vulnerabilities mentioned below
CVE ID
Description
Pre-requisites
CWE
CVSS
CVE-2024-8534
Memory safety vulnerability leading to memory corruption and Denial of Service
The appliance must be configured as a Gateway (VPN Vserver) with RDP Feature enabled ORThe appliance must be configured as a Gateway (VPN Vserver) and RDP Proxy Server Profile is created and set to Gateway (VPN Vserver) ORThe appliance must be configured as a Auth Server (AAA Vserver) with RDP Feature enabled
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVSS v4.0 Base Score: 8.4(CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:L)
CVE-2024-8535
Authenticated user can access unintended user capabilities
The appliance must be configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) with KCDAccount configuration for Kerberos SSO to access backend resourcesOR The appliance must be configured as aAuth Server (AAA Vserver) with KCDAccount configuration for Kerberos SSO to access backend resources
CWE-440: Expected Behavior Violation
CVSS v4.0 Base Score: 5.8(CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:H)
What Customers Should Do
Cloud Software Group strongly urges affected customers of NetScaler ADC and NetScaler Gateway to install the relevant updated versions as soon as possible.
NetScaler ADC and NetScaler Gateway 14.1-29.72 and later releases
NetScaler ADC and NetScaler Gateway 13.1-55.34 and later releases of 13.1
NetScaler ADC 13.1-FIPS 13.1-37.207 and later releases of 13.1-FIPS
NetScaler ADC 12.1-FIPS 12.1-55.321 and later releases of 12.1-FIPS
NetScaler ADC 12.1-NDcPP 12.1-55.321 and later releases of 12.1-NDcPP
Note: NetScaler ADC and NetScaler Gateway versions 12.1 and 13.0 are now End Of Life (EOL) and no longer supported. Customers are recommended to upgrade their appliances to one of the supported versions that address the vulnerabilities.
CVE-2024-8534:
Customers can determine if they have an appliance configured as one of the following by inspecting their ns.conf file for the specified strings
A Gateway (VPN Vserver) with the RDP Feature enabled, enable ns feature.*rdpproxy add vpn vserver
A Gateway (VPN Vserver) with an RDP Proxy Server Profile created and set to the Gateway (VPN Vserver) add rdp serverprofile <RDP_server_name> add vpn vserver <vserver_name> -rdpServerProfileName <RDP_server_name>
An Auth Server (AAA Vserver) with the RDP Feature enabled. enable ns feature.*rdpproxy add authentication vserver
CVE-2024-8535: Customers can determine if they have an appliance configured as one of the following by inspecting their ns.conf file for the specified strings
A Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) with KCDAccount configuration for Kerberos SSO to access backend resources add aaa kcdaccount
An Auth Server (AAA Vserver) with KCDAccount configuration for Kerberos SSO to access backend resources add aaa kcdaccount
In addition, upon upgrading to the fixed version, customers must perform the shell commands mentioned below: nsapimgr_wr.sh -ys call=ns_aaa_flush_kerberos_tickets
Note: In case of High Availability (HA) or Cluster setup of the NetScaler appliances, the above operation should be performed after upgrading all the appliances.
Two vulnerabilities have been discovered in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway).
Affected Versions:
The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities:
NetScaler ADC and NetScaler Gateway 14.1 before 14.1-12.35
NetScaler ADC and NetScaler Gateway 13.1 before 13.1-51.15
NetScaler ADC and NetScaler Gateway 13.0 before 13.0-92.21
NetScaler ADC 13.1-FIPS before 13.1-37.176
NetScaler ADC 12.1-FIPS before 12.1-55.302
NetScaler ADC 12.1-NDcPP before 12.1-55.302
Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End Of Life (EOL) and is vulnerable.
This bulletin only applies to customer-managed NetScaler ADC and NetScaler Gateway products. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.
Summary:
NetScaler ADC and NetScaler Gateway contain the vulnerabilities described below.
CVE ID
Description
Pre-requisites
CWE
CVSS
CVE-2023-6548
Authenticated (low privileged) remote code execution on Management Interface
Access to NSIP, CLIP or SNIP with management interface access
CVE- 2023- 6548 only impacts the management interface. Cloud Software Group strongly recommends that network traffic to the appliance’s management interface is separated, either physically or logically, from normal network traffic. In addition, we recommend that you do not expose the management interface to the internet, as explained in the secure deployment guide. Removing such exposure to the internet greatly reduces the risk of exploitation of this issue. See NetScaler secure deployment guide ( https://docs.citrix.com/en-us/citrix-adc/citrix-adc-secure-deployment/secure-deployment-guide.html) for more information.
What Customers Should Do
Exploits of these CVEs on unmitigated appliances have been observed. Cloud Software Group strongly urges affected customers of NetScaler ADC and NetScaler Gateway to install the relevant updated versions as soon as possible.
NetScaler ADC and NetScaler Gateway 14.1-12.35 and later releases
NetScaler ADC and NetScaler Gateway 13.1-51.15 and later releases of 13.1
NetScaler ADC and NetScaler Gateway 13.0-92.21 and later releases of 13.0
NetScaler ADC 13.1-FIPS 13.1-37.176 and later releases of 13.1-FIPS
NetScaler ADC 12.1-FIPS 12.1-55.302 and later releases of 12.1-FIPS
NetScaler ADC 12.1-NDcPP 12.1-55.302 and later releases of 12.1-NDcPP
Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End Of Life (EOL). Customers are recommended to upgrade their appliances to one supported version that addresses the vulnerabilities.
Es wird empfohlen das Update sobald wie möglich einzuspielen!
Description of Problem
Multiple vulnerabilities have been discovered in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway).
The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities:
NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.13
NetScaler ADC and NetScaler Gateway 13.0 before 13.0-91.13
NetScaler ADC 13.1-FIPS before 13.1-37.159
NetScaler ADC 12.1-FIPS before 12.1-65.36
NetScaler ADC 12.1-NDcPP before 12.65.36
Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End Of Life (EOL) and is vulnerable.
This bulletin only applies to customer-managed NetScaler ADC and NetScaler Gateway. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.
CVE ID
Affected Products
Description
Pre-requisites
CWE
CVSS
CVE-2023-3466
Citrix ADC
Reflected Cross-Site Scripting (XSS)
Requires victim to access an attacker-controlled link in the browser while being on a network with connectivity to the NSIP
Exploits of CVE-2023-3519 on unmitigated appliances have been observed. Cloud Software Group strongly urges affected customers of NetScaler ADC and NetScaler Gateway to install the relevant updated versions as soon as possible.
NetScaler ADC and NetScaler Gateway 13.1-49.13 and later releases
NetScaler ADC and NetScaler Gateway 13.0-91.13 and later releases of 13.0
NetScaler ADC 13.1-FIPS 13.1-37.159 and later releases of 13.1-FIPS
NetScaler ADC 12.1-FIPS 12.1-65.36 and later releases of 12.1-FIPS
NetScaler ADC 12.1-NDcPP 12.1-65.36 and later releases of 12.1-NDcPP
Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End Of Life (EOL). Customers are recommended to upgrade their appliances to one of the supported versions that address the vulnerabilities.
Citrix published on May, 9th a new Security Bulletin for NetScaler ADC and Netscaler Gateway. The severity is rated as medium. AXACOM is recommending to upgrade the NetScaler ADCs and Gateways in the next few days according to the Citrix CTX477714.
Please monitor as well the Citrix CTX article under the following link:
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:
Citrix ADC and Citrix Gateway 13.1 before 13.1-45.61
Citrix ADC and Citrix Gateway 13.0 before 13.0-90.11
Citrix ADC and Citrix Gateway 12.1 before 12.1-65.35
Citrix ADC 12.1-FIPS before 12.1-55.296
Citrix ADC 12.1-NDcPP before 12.1-55.296
This bulletin only applies to customer-managed Citrix ADC and Citrix Gateway. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.
CVE ID
Description
Pre-requisites
CWE
CVSS
CVE-2023-24488
Cross site scripting
Appliance must be configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server
Affected customers of Citrix ADC and Citrix Gateway are recommended to install the relevant updated versions of Citrix ADC or Citrix Gateway as soon as possible:
Citrix ADC and Citrix Gateway 13.1-45.61 and later releases
Citrix ADC and Citrix Gateway 13.0-90.11 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-65.35 and later releases of 12.1
Citrix ADC 12.1-FIPS 12.1-55.296 and later releases of 12.1-FIPS
Citrix ADC 13.1-FIPS 13.1-37.150 and later releases of 13.1-FIPS
Citrix ADC 12.1-NDcPP 12.1-55.296 and later releases of 12.1-NDcPP
Kunden, die auf ihrem NetScaler Kerberos verwenden, bekommen nach dem Microsoft November Update ein Problem. Kerberos funktioniert danach nicht mehr mit dem NetScaler und auch weitere Umsysteme sind davon betroffen. Sie erhalten bei einem Login Versuch via NetScaler folgenden Eintrag im System Eventlog des Domain Controllers:
While processing an AS request for target service <service>, the account <account name> did not have a suitable key for generating a Kerberos ticket (the missing key has an ID of 1). The requested etypes : 18 3. The accounts available etypes : 23 18 17. Changing or resetting the password of <account name> will generate a proper key.
ACHTUNG: Diese Anpassungen sind nur als Workaround zu verstehen und sollten wieder rückgängig gemacht werden, sobald Microsoft einen Fix für den Fehler bereitstellt!
UPDATE 18.11.2022
Microsoft hat ein OOB Update für Domain Controller veröffentlicht, welches das oben beschriebene Problem löst.
Nach der Installation des Updates auf allen Domain Controllern ist es möglich RC4 wieder vom KCD Account zu entfernen (Attribut: msDS-SupportedEncryptionTypes, Value: 24) und falls gesetzt, den Reg Key «KrbtgtFullPacSignature» wieder zu entfernen.
