Overview
Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for a denial-of-service when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.
https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549; https://nvd.nist.gov/vuln/detail/CVE-2023-6549
Key Details
| Property | Value |
|---|---|
| CVE ID | CVE-2023-6549 |
| Vendor / Product | Citrix — NetScaler ADC and NetScaler Gateway |
| NVD Published | 2024-01-17 |
| NVD Last Modified | 2026-02-26 |
| CVSS 3.1 Score | 8.2 |
| CVSS 3.1 Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H |
| Severity | HIGH |
| CWE | CWE-119 |
| CISA KEV Added | 2024-01-17 |
| CISA KEV Deadline | 2024-02-07 |
| Known Ransomware Use | No |
CVSS 3.1 Breakdown
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High
Required Action
CISA BOD 22-01 Deadline: 2024-02-07.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Timeline
| Date | Event |
|---|---|
| 2024-01-17 | Added to CISA Known Exploited Vulnerabilities catalog |
| 2024-02-07 | CISA BOD 22-01 remediation deadline |
References
| Resource | Type |
|---|---|
| NVD — CVE-2023-6549 | Vulnerability Database |
| CISA KEV Catalog Entry | US Government |