CVE-2023-6549
Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
MITRE ATT&CK techniques
How this vulnerability maps to adversary behaviour, from the Center for Threat-Informed Defense's public CVE→ATT&CK mappings. Use it to check whether your detections already cover the technique.
Summary
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.
Affected software
Vendor: Citrix · Product: NetScaler ADC and NetScaler Gateway
Weakness types (CWE):
What to do
This vulnerability appears in CISA's Known Exploited Vulnerabilities catalog, meaning it is being exploited in the wild. Prioritize patching affected systems and verify exposure across your estate.
Related vulnerabilities in Citrix
| CVE | Name | EPSS | Exploited |
|---|---|---|---|
| CVE-2023-4966 | Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability | 100.0% | Yes |
| CVE-2019-19781 | Citrix ADC, Gateway, and SD-WAN WANOP Appliance Code Execution Vulnerability | 100.0% | Yes |
| CVE-2025-5777 | Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability | 99.9% | Yes |
| CVE-2023-3519 | Citrix NetScaler ADC and NetScaler Gateway Code Injection Vulnerability | 99.7% | Yes |
| CVE-2023-24489 | Citrix Content Collaboration ShareFile Improper Access Control Vulnerability | 94.4% | Yes |
| CVE-2019-12989 | Citrix SD-WAN and NetScaler SQL Injection Vulnerability | 94.1% | Yes |
| CVE-2020-8193 | Citrix ADC, Gateway, and SD-WAN WANOP Appliance Authorization Bypass Vulnerabili | 88.4% | Yes |
| CVE-2026-3055 | Citrix NetScaler Out-of-Bounds Read Vulnerability | 78.3% | Yes |
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