Application Delivery Controller Firmware
CVE-2021-22955
HIGH
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
1DescriptionNVD
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.
AnalysisAI
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. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Technical ContextAI
This vulnerability is classified as Uncontrolled Resource Consumption (CWE-400), which allows attackers to cause denial of service by exhausting system resources. 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. Affected products include: Citrix Application Delivery Controller Firmware, Citrix Gateway.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement rate limiting, set resource quotas, validate input sizes, use timeouts.
Citrix NetScaler Application Delivery Controller (ADC) and NetScaler Gateway 10.5 before build 67.13, 11.0 before build
Improper input validation in Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.1
Reflected code injection in Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.14
Improper access control in Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.14
Improper input validation in Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21, 11.1-64.1
User login brute force protection functionality bypass. Rated critical severity (CVSS 9.8), this vulnerability is remote
Unauthorized access to Gateway user capabilities. Rated critical severity (CVSS 9.8), this vulnerability is remotely exp
An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway before 10.5 build 70.8, 11.x before
The AppFirewall functionality in Citrix NetScaler Application Delivery Controller and NetScaler Gateway 10.5 before Buil
Remote desktop takeover via phishing. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, no
Citrix ADC and Citrix Gateway 13.0 before 13.0-64.35, Citrix ADC and NetScaler Gateway 12.1 before 12.1-58.15, Citrix AD
Privilege escalation vulnerability on Citrix ADC and Citrix Gateway versions before 13.0-58.30, 12.1-57.18, 12.0-63.21,
Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today