Buffer overflow in Citrix Netscaler Adc
CVE-2023-4966
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.
EPSS exploit prediction
EPSS: 1.000 (100.0th percentile), scored .
Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 100.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
- Citrix Netscaler Adc — versions 14.1, 13.1, 13.0
- Citrix Netscaler Application Delivery Controller
- Citrix Netscaler Gateway — versions 14.1, 13.1, 13.0
- Citrix Netscaler Gateway
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- support.citrix.com/article/CTX579459 (Vendor Advisory)
- packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-O… (VDB Entry, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2023-4966?
- CVE-2023-4966 is a critical-severity vulnerability in Citrix Netscaler Adc, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.4/10. Published 2023-10-10.
- How severe is CVE-2023-4966?
- Critical severity. CVSS v3 base score is 9.4 out of 10.
- Is CVE-2023-4966 known to be exploited?
- Yes. CVE-2023-4966 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-18), indicating it is being actively exploited. 57 public proof-of-concept repositories are indexed.