CVE-2023-6549
Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 7 February 2024). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 57.63% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 17 January 2024 · due 7 February 2024
- Weakness
- CWE-119
- Affected
- citrix/netscaler application delivery controller · citrix/netscaler gateway
- Source
- secure@citrix.com
EPSS 57.6% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. 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
References
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549Vendor Advisory
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-6549US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.