CVE-2025-7775
📋 TL;DR
A memory overflow vulnerability in NetScaler ADC and NetScaler Gateway allows remote attackers to execute arbitrary code or cause denial of service. Affected systems include those configured as VPN gateways, AAA servers, or load balancers with specific IPv6 configurations. This vulnerability affects multiple versions including 13.1 and 14.1.
💻 Affected Systems
- NetScaler ADC
- NetScaler Gateway
📦 What is this software?
Netscaler Application Delivery Controller by Citrix
View all CVEs affecting Netscaler Application Delivery Controller →
Netscaler Application Delivery Controller by Citrix
View all CVEs affecting Netscaler Application Delivery Controller →
Netscaler Application Delivery Controller by Citrix
View all CVEs affecting Netscaler Application Delivery Controller →
Netscaler Application Delivery Controller by Citrix
View all CVEs affecting Netscaler Application Delivery Controller →
Netscaler Application Delivery Controller by Citrix
View all CVEs affecting Netscaler Application Delivery Controller →
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data exfiltration, and lateral movement within the network.
Likely Case
Denial of service causing service disruption for VPN users and load-balanced applications.
If Mitigated
Limited impact with proper network segmentation and intrusion prevention systems in place.
🎯 Exploit Status
CISA has added this to their Known Exploited Vulnerabilities catalog, indicating active exploitation is likely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Citrix advisory CTX694938 for specific fixed versions
Vendor Advisory: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694938
Restart Required: Yes
Instructions:
1. Review Citrix advisory CTX694938. 2. Download appropriate firmware updates. 3. Apply patches during maintenance window. 4. Reboot affected appliances.
🔧 Temporary Workarounds
Disable IPv6 on vulnerable configurations
allRemove IPv6 bindings from affected LB virtual servers and service groups
nscli -U <nsroot> -P <password> -s <NSIP> -c "unbind lb vserver <vserver_name> -serviceName <service_name> -ipv6"
Network segmentation
allRestrict access to vulnerable services using firewall rules
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure to vulnerable services
- Deploy intrusion prevention systems with signatures for this CVE
🔍 How to Verify
Check if Vulnerable:
Check NetScaler configuration for vulnerable setups: Gateway virtual servers, AAA virtual servers, or LB virtual servers with IPv6 bindingsCheck Version:
nscli -U <nsroot> -P <password> -s <NSIP> -c "show ns version"Verify Fix Applied:
Verify firmware version is updated to patched version and vulnerable configurations are removed📡 Detection & Monitoring
Log Indicators:
- Unusual memory allocation patterns
- Crash logs from NetScaler processes
- Failed service restarts
Network Indicators:
- Unexpected connections to vulnerable ports
- Malformed IPv6 packets to NetScaler services
SIEM Query:
source="netscaler*" AND (event_type="CRASH" OR memory_usage>threshold) OR dest_port IN (80, 443, 2598) AND ip_version=6