CVE-2021-22919

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-08-05 · updated 2026-06-17
Weakness: CWE-770

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 the limited available disk space on the appliances being fully consumed.

Affected products

Citrix Application Delivery Controller Firmware: from 11.1 before 11.1-65.22; from 12.1 before 12.1-62.27; from 13.0 before 13.0-82.45; from 12.1 before 12.1-55.238 — fixed in 11.1-65.22, 12.1-62.27, 13.0-82.45, 12.1-55.238
NetScaler Gateway: from 12.1 before 12.1-62.27; from 13.0 before 13.0-82.45 — fixed in 12.1-62.27, 13.0-82.45
Citrix NetScaler Gateway: from 11.1 before 11.1-65.22 — fixed in 11.1-65.22
Citrix Sd-Wan Wanop: from 10.2 before 10.2.9.b; from 11.2 before 11.2.3.b; from 11.3 before 11.3.2.a; from 11.4 before 11.4.0.a — fixed in 10.2.9.b, 11.2.3.b, 11.3.2.a, 11.4.0.a
Citrix ADC, Citrix Gateway, Citrix SD-WAN WANOP: 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

How to fix

Upgrade to a fixed version: Citrix Application Delivery Controller Firmware 11.1-65.22, 12.1-62.27, 13.0-82.45, 12.1-55.238; NetScaler Gateway 12.1-62.27, 13.0-82.45; Citrix NetScaler Gateway 11.1-65.22; Citrix Sd-Wan Wanop 10.2.9.b, 11.2.3.b, 11.3.2.a, 11.4.0.a. Check the vendor advisory for mitigations.

References

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