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Helient Systems : Citrix ADC (NetScaler) New Security Vulnerabilities

Daniel Ruiz

July 19, 2021

by Daniel Ruiz
Senior Solutions Architect

Multiple vulnerabilities have been discovered in Citrix ADC (formerly known as NetScaler) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO.

Citrix strongly recommends that affected customers install relevant updates as soon as possible. If exploited could result in the following security issues.

Vulnerabilities:

CVE-2021-22919 – Unauthenticated requests leading to limited disk space consumption on the appliance
CVE-2021-22920 – SAML authentication hijack through a phishing attack to steal a valid user session.
CVE-2021-22927 – Session fixation by an authorized user on SAML SP

Affected by CVE-2021-22919:

Citrix ADC and Citrix Gateway 13.0 before 13.0-82.45
Citrix ADC and Citrix Gateway 12.1 before 12.1-62.27
Citrix ADC and NetScaler Gateway 11.1 before 11.1-65.22
Citrix ADC 12.1-FIPS before 12.1-55.247
Citrix SD-WAN WANOP Edition 11.4 before 11.4.0.a
Citrix SD-WAN WANOP Edition 11.3 before 11.3.2.a
Citrix SD-WAN WANOP Edition 11.2 before 11.2.3.b
Citrix SD-WAN WANOP Edition 10.2 before 10.2.9.b

Affected by CVE-2021-22920:

Citrix ADC and Citrix Gateway 13.0-82.42
Citrix ADC and Citrix Gateway 12.1-62.25

Affected by CVE-2021-22927:

Citrix ADC and Citrix Gateway 13.0 before 13.0-82.45
Citrix ADC and Citrix Gateway 12.1 before 12.1-62.27
Citrix ADC and NetScaler Gateway 11.1 before 11.1-65.22
Citrix ADC 12.1-FIPS before 12.1-55.247

Fix to address CVE-2021-22919:

Upgrade firmware to the following versions:

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1
Citrix ADC and NetScaler Gateway 11.1-65.22 and later releases of 11.1
Citrix ADC 12.1-FIPS 12.1-55.247 and later releases of 12.1-FIPS
Citrix SD-WAN WANOP Edition 11.4.0a and later releases of 11.4
Citrix SD-WAN WANOP Edition 11.3.2a and later releases of 11.3
Citrix SD-WAN WANOP Edition 11.2.3b and later releases of 11.2
Citrix SD-WAN WANOP Edition 10.2.9b and later releases of 10.2

Fix to address CVE-2021-22920

Upgrade firmware to the following versions:

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1

Fix to address CVE-2021-22927

Upgrade firmware to the following versions:

Citrix ADC and Citrix Gateway 13.0-82.45 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-62.27 and later releases of 12.1
Citrix ADC and NetScaler Gateway 11.1-65.22 and later releases of 11.1
Citrix ADC 12.1-FIPS 12.1-55.247 and later releases of 12.1-FIPS

If you would like more information or assistance from our industry leading team of Citrix experts to plan and execute the upgrade, please contact us at service@helient.com.