Known exploited vulnerability
CVE-2023-4966
The short answer
CVE-2023-4966 affects Citrix NetScaler ADC and is rated high (CVSS 7.5). CISA added it to the Known Exploited Vulnerabilities catalog on 2023-10-18: attackers are using it, so patch it first.
What it is
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.
Weakness: CWE-119.
Severity
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploited (CISA KEV)
Yes, since Oct 18, 2023
Federal due date Nov 8, 2023
EPSS, next 30 days
100%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
What CISA says to do
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.
Affected products
NetScaler ADC, NetScaler Gateway. NVD's record lists the exact affected versions.
References
- support.citrix.com/article/CTX579459 Vendor Advisory
- support.citrix.com/article/CTX579459 Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4966 US Government Resource
Questions
Is CVE-2023-4966 being exploited?
Yes. CISA added CVE-2023-4966 to its Known Exploited Vulnerabilities catalog on 2023-10-18, with a federal remediation due date of 2023-11-08. CISA lists it as used in ransomware campaigns.
How do I fix CVE-2023-4966?
CISA's 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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