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Vulnerability record · CVE-2021-22920 · published 5 August 2021

CVE-2021-22920: Citrix application delivery management improper access control vulnerability

Citrix · Application Delivery Management

A vulnerability has been discovered in Citrix ADC (formerly known as NetScaler ADC) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO. These vulnerabilities, if exploited, could lead to a phishing attack through a SAML authentication hijack to steal a valid user session.

6.5 CVSS 3.1 Medium EPSS 0.92% · top 41.3% CWE-284 · Improper access control
6.5CVSS 3.1 base score, v2 4.3
0.92%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A vulnerability has been discovered in Citrix ADC (formerly known as NetScaler ADC) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO. These vulnerabilities, if exploited, could lead to a phishing attack through a SAML authentication hijack to steal a valid user session.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://support.citrix.com/article/CTX319135 Vendor Advisory
https://support.citrix.com/article/CTX319135 Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2019-9548Citrix application delivery management vulnerabilityCitrix Application Delivery Management (ADM) 12.1.x before 12.1.50.33 has Incorrect Access Control.EPSS 1.5%9.8CVE-2022-27510Citrix gateway authentication bypass via alternate path vulnerabilityUnauthorized access to Gateway user capabilitiesEPSS 1.1%9.8CVE-2022-27516Citrix gateway improper restriction of authentication attempts vulnerabilityUser login brute force protection functionality bypassEPSS 0.64%9.6CVE-2022-27513Citrix gateway insufficient verification of data authenticity vulnerabilityRemote desktop takeover via phishingEPSS 0.29%8.8CVE-2020-8247Citrix application delivery controller firmware improper privilege management vulnerabilityCitrix ADC and Citrix Gateway 13.0 before 13.0-64.35, Citrix ADC and NetScaler Gateway 12.1 before 12.1-58.15, Citrix ADC 12.1-FIPS before 12.1-55.18…EPSS 1.4%8.8CVE-2019-17366Citrix application delivery management vulnerabilityCitrix Application Delivery Management (ADM) 12.1 before build 54.13 has Incorrect Access Control.EPSS 1.3%8.1CVE-2022-27511Citrix application delivery management improper access control vulnerabilityCorruption of the system by a remote, unauthenticated user. The impact of this can include the reset of the administrator password at the next device…EPSS 12%8.1CVE-2021-22927Citrix application delivery controller firmware vulnerabilityA session fixation vulnerability exists in Citrix ADC and Citrix Gateway 13.0-82.45 when configured SAML service provider that could allow an attacke…EPSS 0.84%

Source: NIST National Vulnerability Database (record CVE-2021-22920), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.