Citrix has identified an isolated issue in which some customers experienced a crash condition after upgrading to the current build with HTTP/2 enabled.
What Product is Affected?
NetScaler appliance upgraded to version NS13.1 Build 45.63 or NS13.0 Build 90.11
*No other versions are impacted by this HTTP/2 issue.
Is there a workaround or fix?
Workaround: Disable http2 in the HTTP profile bound to the virtual server.
Fix: Engineering is working on a code fix and will update the ETA of the next build as soon as possible.
How to verify if http2 is enabled?
Run the following command from the CLI and verify if http2Direct Is reported as enabled.
> show run | grep http2
Example of output if enabled:
> set ns httpProfile <name of httpprofile> -http2 ENABLED -http2Direct ENABLED
Example of output if not enabled:
> set ns httpProfile <name of httpprofile> -http2 DISABLED -http2Direct DISABLED
How to disable http2 if enabled?
> set ns httpProfile <name of the httpprofile> -http2 DISABLED -http2Direct DISABLED
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
A vulnerability has been discovered in Citrix Gateway and Citrix ADC, listed below, that, if exploited, could allow an unauthenticated remote attacker to perform arbitrary code execution on the appliance.
CVE-ID
Description
CWE
Affected Products
Pre-conditions
CVE-2022-27518
Unauthenticated remote arbitrary code execution
CWE-664: Improper Control of a Resource Through its Lifetime
Citrix Gateway, Citrix ADC
Citrix ADC or Citrix Gateway must be configured as a SAML SP or a SAML IdP
The following supported versions of Citrix ADC and Citrix Gateway are affected by this vulnerability:
Citrix ADC and Citrix Gateway 13.0 before 13.0-58.32
Citrix ADC and Citrix Gateway 12.1 before 12.1-65.25
Citrix ADC 12.1-FIPS before 12.1-55.291
Citrix ADC 12.1-NDcPP before 12.1-55.291
Citrix ADC and Citrix Gateway version 13.1 is unaffected.
What Customers Should Do
Exploits of this issue on unmitigated appliances in the wild have been reported. Citrix strongly urges affected customers of Citrix ADC and Citrix Gateway to install the relevant updated versions of Citrix ADC or Citrix Gateway as soon as possible:
Citrix ADC and Citrix Gateway 13.0-58.32 and later releases
Citrix ADC and Citrix Gateway 12.1-65.25 and later releases of 12.1
Citrix ADC 12.1-FIPS 12.1-55.291 and later releases of 12.1-FIPS
Citrix ADC 12.1-NDcPP 12.1-55.291 and later releases of 12.1-NDcPP
Please note that Citrix ADC and Citrix Gateway versions prior to 12.1 are EOL and customers on those versions are recommended to upgrade to one of the supported versions.
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.
Vulnerabilities have been discovered in Citrix Gateway and Citrix ADC, listed below. Note that only appliances that are operating as a Gateway (appliances using the SSL VPN functionality or deployed as an ICA proxy with authentication enabled) are affected by the first issue, which is rated as a Critical severity vulnerability.
CVE-ID
Description
CWE
Affected Products
Pre-conditions
CVE-2022-27510
Unauthorized access to Gateway user capabilities
CWE-288: Authentication Bypass Using an Alternate Path or Channel
Citrix Gateway, Citrix ADC
Appliance must be configured as a VPN (Gateway)
CVE-2022-27513
Remote desktop takeover via phishing
CWE-345: Insufficient Verification of Data Authenticity
Citrix Gateway, Citrix ADC
Appliance must be configured as a VPN (Gateway) and the RDP proxy functionality must be configured
CVE-2022-27516
User login brute force protection functionality bypass
CWE-693: Protection Mechanism Failure
Citrix Gateway, Citrix ADC
Appliance must be configured as a VPN (Gateway) OR AAA virtual server and the user lockout functionality “Max Login Attempts” must be configured
The following supported versions of Citrix ADC and Citrix Gateway are affected by this vulnerability:
Citrix ADC and Citrix Gateway 13.1 before 13.1-33.47
Citrix ADC and Citrix Gateway 13.0 before 13.0-88.12
Citrix ADC and Citrix Gateway 12.1 before 12.1.65.21
Citrix ADC 12.1-FIPS before 12.1-55.289
Citrix ADC 12.1-NDcPP before 12.1-55.289
This bulletin only applies to customer-managed Citrix ADC and Citrix Gateway appliances. Customers using Citrix-managed cloud services do not need to take any action.
Microsoft is investigating two reported zero-day vulnerabilities affecting Microsoft Exchange Server 2013, 2016, and 2019. The first vulnerability, identified as CVE-2022-41040, is a Server-Side Request Forgery (SSRF) vulnerability, while the second, identified as CVE-2022-41082, allows remote code execution (RCE) when PowerShell is accessible to the attacker.
What Customers Should Do
To protect your on-prem Exchange you can bind a responder policy on the Citrix ADC contentswitch handling all the Exchange related traffic:
