Uncontrolled resource consumption in Citrix ADC, Citrix Gateway
Priority LOW 35CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-400.
Summary
A unauthenticated denial of service vulnerability exists in Citrix ADC <13.0-83.27, <12.1-63.22 and 11.1-65.23 when configured as a VPN (Gateway) or AAA virtual server could allow an attacker to cause a temporary disruption of the Management GUI, Nitro API, and RPC communication.
Why it matters now
EPSS 0.0092 60th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Citrix ADC, Citrix Gateway | Citrix ADC 111.1, 2.1, 13.0,13.1 | — | No fix listed | CNA |
- Citrix ADC, Citrix Gateway Vendor— Affected Citrix ADC 111.1, 2.1, 13.0,13.1 Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:citrix:application_delivery_controller_firmware:*:*:*:*:*:*:*:* | up to 11.1-65.23; 12.1 to before 12.1-63.22; 13.0 to before 13.0-83.27 | Vulnerable | Citrix |
| cpe:2.3:h:citrix:application_delivery_controller:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Citrix |
| cpe:2.3:a:citrix:gateway:*:*:*:*:*:*:*:* | before 11.1-65.23; 12.1 to before 12.1-63.22; 13.0 to before 13.0-83.27 | Vulnerable | Citrix |
- cpe:2.3:o:citrix:application_delivery_controller_firmware:*:*:*:*:*:*:*:* Versions up to 11.1-65.23; 12.1 to before 12.1-63.22; 13.0 to before 13.0-83.27 Vulnerable ·Citrix
- cpe:2.3:h:citrix:application_delivery_controller:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Citrix
- cpe:2.3:a:citrix:gateway:*:*:*:*:*:*:*:* Versions before 11.1-65.23; 12.1 to before 12.1-63.22; 13.0 to before 13.0-83.27 Vulnerable ·Citrix
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-22955
- 2026-10-03 Alias added: GHSA-xwgf-rg8j-2j5x
References
More Citrix Application Delivery Controller Firmware vulnerabilities
- TI-2022-10528 Unauthenticated remote arbitrary code execution in Citrix Gateway, Citrix ADC KEVCVSS 3.1CRITICAL 9.8
- TI-2019-14254 An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway 10.5… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-06613 Improper input validation in Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP KEVCVSS 3.1MEDIUM 6.5
- TI-2020-06611 Improper access control in Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP KEVCVSS 3.1MEDIUM 6.5
- TI-2020-06614 Improper access control in Citrix ADC, Citrix Gateway, Citrix SDWAN WAN-OP KEVCVSS 3.1MEDIUM 4.3
- TI-2018-05232 The AppFirewall functionality in Citrix NetScaler Application Delivery Controller and… CVSS 3.0CRITICAL 9.8
Sources
- CVE-2021-22955 · CVE Program
- CVE-2021-22955 · NVD
- FIRST EPSS
- GHSA-xwgf-rg8j-2j5x · GitHub Advisory Database · CC BY 4.0
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