CVEs / CVE-2023-6549
CVE-2023-6549: Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
- Known exploited in the CISA KEV catalog since 17 Jan 2024
- high 7.5 CVSS 3.1 (NVD)
- EPSS 57.6% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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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.
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
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cloud Software Group NetScaler ADC | from 14.1, before 12.35 | 12.35 |
| Cloud Software Group NetScaler ADC | from 13.1, before 51.15 | 51.15 |
| Cloud Software Group NetScaler ADC | from 13.0, before 92.21 | 92.21 |
| Cloud Software Group NetScaler ADC | from 13.1-FIPS, before 37.176 | 37.176 |
| Cloud Software Group NetScaler ADC | from 12.1-FIPS, before 55.302 | 55.302 |
| Cloud Software Group NetScaler ADC | from 12.1-NDcPP, before 55.302 | 55.302 |
Exploitation
| In CISA KEV since | 17 Jan 2024 |
|---|---|
| Due date for US federal agencies | 7 Feb 2024 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. |
Severity
| CVSS 3.1 | 7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HScored by NVD |
|---|---|
| Weakness | CWE-119 |
References
- CVE-2023-6549 on NVD
- CVE-2023-6549 in the CISA KEV catalog
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549 (cited by CISA)
- https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-6549 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.