Pierluigi Paganini August 27, 2025

U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Citrix NetScaler flaw to its Known Exploited Vulnerabilities catalog.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added Citrix NetScaler flaw, tracked as CVE-2025-7775, to its Known Exploited Vulnerabilities (KEV) catalog.

This week, Citrix addressed three security flaws (CVE-2025-7775, CVE-2025-7776, CVE-2025-8424) in NetScaler ADC and NetScaler Gateway, including one (CVE-2025-7775) that it said has been actively exploited in the wild.

“Exploits of CVE-2025-7775 on unmitigated appliances have been observed.” reads the advisory.

Below is the description for these vulnerabilities:

• CVE-2025-7775 (CVSS score: 9.2) – Memory overflow vulnerability leading to Remote Code Execution and/or Denial-of-Service. Pre-conditions for exploitation: NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server; NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with IPv6 services or servicegroups bound with IPv6 servers; NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with DBS IPv6 services or servicegroups bound with IPv6 DBS servers; or CR virtual server with type HDX
• CVE-2025-7776 (CVSS score: 8.8) – Memory overflow vulnerability leading to unpredictable or erroneous behavior and Denial of Service. Pre-conditions for exploitation: NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) with PCoIP Profile bounded to it. 
• CVE-2025-8424 (CVSS score: 8.7) – Improper access control on the NetScaler Management Interface. Pre-conditions for exploitation: Access to NSIP, Cluster Management IP or local GSLB Site IP or SNIP with Management Access.

The company did not provide details about the attacks that exploited the flaw CVE-2025-7775.

Cloud Software Group urges NetScaler ADC and NetScaler Gateway customers to promptly update to secure versions: 14.1-47.48+, 13.1-59.22+, 13.1-FIPS/NDcPP 13.1-37.241+, and 12.1-FIPS/NDcPP 12.1-55.330+. Installing these updates is critical to mitigate security risks.

The vendor states that no workarounds are available.

According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog.

Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure.

CISA orders federal agencies to fix the vulnerabilities by August 28, 2025.

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Pierluigi Paganini

(SecurityAffairs – hacking, CISA)