CVE-2023-6549
Published 2024-01-17 · Updated 2026-06-17 · Source secure@citrix.com
Summary
CVE-2023-6549 is a high-severity (CVSS 8.2) vulnerability in Citrix NetScaler ADC and NetScaler Gateway. CISA added it to the Known Exploited Vulnerabilities catalog on January 17, 2024, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by February 7, 2024. CISA does not currently list it as used in ransomware campaigns. Citrix has 27 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.
All 27 known-exploited Citrix vulnerabilities →Description
Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
CISA Known-Exploited Vulnerability
Product: Citrix — NetScaler ADC and NetScaler Gateway
Name: Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
Date added: 2024-01-17 · Due: 2024-02-07
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
References
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-6549