# Citrix NetScaler ADC and NetScaler Gateway: 2 actively exploited vulnerabilities · pwn.watch

> CVE-2023-6548: Citrix NetScaler ADC and NetScaler Gateway contain a code injection vulnerability that allows for authenticated remote code execution on the management interface with access to NSIP, CLIP, or SNIP. CVE-2023-6549: 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. Added to the CISA KEV catalog on 2024-01-17. CVE-2023-6548, CVE-2023-6549 were assigned before 2024; the KEV listing came in 2024.

Page: https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549 · generated 2026-10-22T20:45:43.249Z

## Status
- Severity: high · status: closed · patch: patched
- Product: Citrix NetScaler ADC and NetScaler Gateway
- Started: 2024-01-17 · closed: 2024-01-17
- CVEs: CVE-2023-6548, CVE-2023-6549
- Affected: See vendor advisory (versions are not listed in the KEV record)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549/feed.xml
- JSON Feed: https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549.json
- This file: https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549/llms.txt

## Updates (newest first)
- 2024-01-17: CVE-2023-6548 published (https://nvd.nist.gov/vuln/detail/CVE-2023-6548)
- 2024-01-17: CVE-2023-6549 published (https://nvd.nist.gov/vuln/detail/CVE-2023-6549)
- 2024-01-17: CISA added CVE-2023-6548 to the KEV catalog (federal deadline 2024-01-24) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)
- 2024-01-17: CISA added CVE-2023-6549 to the KEV catalog (federal deadline 2024-02-07) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)

## Fix brief
# Security brief: Citrix NetScaler ADC and NetScaler Gateway: 2 actively exploited vulnerabilities

Source: https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549 · status: closed (closed Jan 17, 2024) · severity: high · updated Jan 17, 2024

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
CVE-2023-6548: Citrix NetScaler ADC and NetScaler Gateway contain a code injection vulnerability that allows for authenticated remote code execution on the management interface with access to NSIP, CLIP, or SNIP. CVE-2023-6549: 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. Added to the CISA KEV catalog on 2024-01-17. CVE-2023-6548, CVE-2023-6549 were assigned before 2024; the KEV listing came in 2024.

Severity detail: CVSS 8.2 (v3.1, CNA), actively exploited (CISA KEV)

- Product: Citrix NetScaler ADC and NetScaler Gateway
- CVE / advisory ids: CVE-2023-6548, CVE-2023-6549

## Affected versions
- See vendor advisory (versions are not listed in the KEV record)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Jan 17, 2024: CVE-2023-6548 published
- Jan 17, 2024: CVE-2023-6549 published
- Jan 17, 2024: CISA added CVE-2023-6548 to the KEV catalog (federal deadline 2024-01-24)
- Jan 17, 2024: CISA added CVE-2023-6549 to the KEV catalog (federal deadline 2024-02-07)

## Advisories
- [Citrix advisory: CVE-2023-6548](https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549) (Citrix)
- [NVD: CVE-2023-6548](https://nvd.nist.gov/vuln/detail/CVE-2023-6548) (NVD)
- [NVD: CVE-2023-6549](https://nvd.nist.gov/vuln/detail/CVE-2023-6549) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from the CISA KEV JSON feed (catalogVersion 2026.10.21); CVSS from the CVE record (cveawg.mitre.org). startedAt is the CVE publication date when it fell in 2024 before the KEV listing, else the KEV dateAdded; exploitation may have begun earlier. closedAt is the KEV listing date (a fix or mitigation was available then unless noted).

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Machine-readable: https://pwn.watch/i/citrix-netscaler-adc-and-netscaler-gatew-cve-2023-6548-6549.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.