overview
CVE-2025-7775 is a critical memory overflow vulnerability in Citrix NetScaler ADC and NetScaler Gateway that enables unauthenticated remote code execution (RCE) and/or denial of service (DoS). The vulnerability is being actively exploited and poses severe risks—particularly to organizations in the retail, healthcare, and financial sectors.
Vulnerability Description
CVE-2025-7775 impacts Citrix NetScaler ADC and Gateway appliances when configured with:
- Gateway or AAA virtual servers
- Certain load balancing virtual servers with IPv6/DBS IPv6 services
- CR virtual servers of type HDX
Exploitation allows a remote, unauthenticated attacker to execute arbitrary code on the device or cause a system crash, resulting in Denial of Service.
Potential Impact
- Unauthorized remote code execution (full compromise)
- Denial of Service (service outage/disruption)
- Persistent backdoors (web shell deployment or stealthy access—sometimes surviving patching)
- Broad impact on critical industries, but risk extends to any organization with affected NetScaler devices
Attack Vector & Exploitation
- Attackers exploit this vulnerability remotely, without authentication.
- Appliances must be configured in a vulnerable virtual server mode.
- While the attack complexity is high (due to challenges in exploiting memory corruption), active exploitation is confirmed.
- Threat actors have deployed persistent access mechanisms, remaining through some patching cycles.
affected products and versions
- Citrix NetScaler ADC
- Citrix NetScaler Gateway
Vulnerable Versions:
- 1 — prior to 14.1-47.48
- 1 — prior to 13.1-59.22
- 1-FIPS and NDcPP — prior to 13.1-37.241-FIPS/NDcPP
- 1-FIPS and NDcPP — prior to 12.1-55.330-FIPS/NDcPP
Patched Versions:
- 1-47.48 and above
- 1-59.22 and above
- 1-37.241-FIPS/NDcPP and above
- 1-55.330-FIPS/NDcPP and above
Threat status
- Exploited in the wild: Exploitation began before patch release.
- Observed incidents: Deployment of persistent backdoors/web shells, often leaving over 28,000 unpatched appliances
- Techniques: Remote code execution for persistence or lateral movement; Denial of Service for disruption.
- Targeted industries: Primarily retail, healthcare, financial; all sectors using NetScaler at risk.
- Proof of Concept (PoC): No known public exploit yet, but intelligence sources expect rapid emergence.
INDICATORS OF COMPROMISE (IOCS)
Currently, there are no confirmed, publicly disclosed IOCs specifically tied to successful CVE-2025-7775 exploitation. Neither Citrix nor research teams have released related IP addresses, domain names, file hashes, or malware signatures.
Forensic and Monitoring Insights
- Ongoing investigations continue across research, threat intel, and Citrix teams to identify relevant IOCs.
- Exploitation may leave web shells or result in repeated malformed requests to NetScaler endpoints, but no detailed forensic artifacts have been published.
- Avertium actively monitors and will disclose IOCs as soon as they are located.
Where to Monitor IOC Updates
- Citrix official security advisories
- SOC Prime Platform global threats feed
- Industry news outlets (e.g., BleepingComputer)
- Threat intelligence providers like Arctic Wolf and Rapid7
For direct Avertium support, contact your Service Delivery Manager or Account Executive.
MITRE ATT&CK ttPS
Below are key MITRE ATT&CK tactics and techniques associated with exploitation of CVE-2025-7775, based on vulnerability nature and typical attack behaviors:
Initial Access
- T1190 — Exploit Public-Facing Application:
Memory overflow on NetScaler allows attackers to gain initial, unauthenticated access through exposed services.
Execution
- T1059 — Command and Scripting Interpreter:
After exploiting, attackers may execute arbitrary commands via shell/scripting interpreters.
- T1203 — Exploitation for Client Execution:
Forced execution of malicious payloads directly on the target device.
Persistence
- T1546 — Event Triggered Execution:
Use of scheduled tasks, cron jobs, or startup scripts for persistence.
- T1053 — Scheduled Task/Job:
If possible, attackers install scheduled jobs to maintain access post-reboot or patch.
Privilege Escalation
- T1068 — Exploitation for Privilege Escalation:
If compromise occurs under limited privileges, further exploits may seek system/root access.
Defense Evasion
- T1218 — System Binary Proxy Execution:
Abuse of Citrix-native binaries or libraries to evade detection.
- T1140 — Deobfuscate/Decode Files or Information:
Payloads may be encoded to bypass monitoring.
Impact
- T1499 — Endpoint Denial of Service:
Exploit can directly crash devices or applications, disrupting services.
- T1485 — Data Destruction:
Attackers could corrupt or delete configurations, causing service outages.
For SIEM integration, detection guidance, and further triage, platforms like SOC Prime provide ATT&CK-mapped analytic rules.
additional Recommendations + information
Immediate Mitigation Measures
- Apply Citrix patches immediately:
Upgrade to the latest patched versions:
- 1-47.48+
- 1-59.22+
- 1-FIPS/NDcPP 13.1-37.241+
- 1-FIPS/NDcPP 12.1-55.330+
- Restrict internet exposure:
Shield exposed virtual servers (Gateway, VPN, LB) behind firewalls when possible.
- Limit Gateway/AAA functionality:
Disable or restrict features to necessary internal users only.
- Review IPv6 bindings:
Disable unused IPv6 support, especially for external access.
- Protect admin interfaces:
Segment management interfaces from untrusted networks; use strong authentication.
Patch and System Monitoring
- Monitor vendor advisories:
Keep tracking Citrix releases for fixes and emergent mitigation steps.
- Network monitoring:
Deploy sensors to detect signs of exploitation or anomalous traffic, including backdoor/persistent access attempts.
- SIEM integration:
Ingest NetScaler logs for real-time alerting and forensic review.
Network Security Enhancements
- Block malicious IPs:
Use threat intelligence (Shadowserver, CISA) to block known attacker infrastructure.
- Intrusion detection/prevention:
Enable IDS/IPS rules for Citrix vulnerabilities.
- Isolate vulnerable assets:
Segment unpatched appliances; restrict external connectivity.
- Run continuous vulnerability scans:
Proactively identify and remediate unpatched systems.
- Hunt for abuse artifacts:
Look for new accounts/configuration changes indicating persistent attacker footholds.
ADDITIONAL SERVICE OFFERINGS
Avertium offers specialized services to help organizations rapidly defend against and recover from attacks like those exploiting CVE-2025-7775:
- Threat Detection & Response (TDR):
Proactive detection and XDR-informed response for vulnerabilities like CVE-2025-7775. Quickly identifies exploit attempts, maps them to MITRE ATT&CK, and provides rapid containment and remediation to strengthen resilience.
- Security Information and Event Management (SIEM):
Centralized monitoring and alerting for anomalous Citrix activity. SIEM enables detection of lateral movement, data exfiltration, and compliance reporting by aggregating NetScaler logs and automating incident response.
- Cybersecurity Strategy Services:
Aligns organizational risk management with frameworks like MITRE ATT&CK, providing:
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- Strategic Security Assessments: Identify exposure to memory overflow attacks and create targeted mitigation plans.
- Threat Mapping: Relate real-world threats to your environment and prioritize remediation.
- Cyber Maturity Roadmap: Build policies and resilience strategies for business continuity during critical incidents.
- Attack Surface Management (ASM):
Routine identification, prioritization, and mitigation of vulnerabilities in internet-facing services, including Citrix. ASM limits opportunity for unauthenticated exploitation and enhances defensive posture.
- Governance, Risk, and Compliance (GRC):
Expertise in aligning with regulations (PCI DSS, HIPAA, GDPR). Provides audits, incident response capability, and documentation to satisfy compliance requirements in at-risk sectors.
- Security Operations Center (SOC) – Guadalajara, Mexico:
Regional, 24/7 threat monitoring and rapid incident handling for Latin America and global clients—improving time-to-detection and minimizing harmful impacts from NetScaler vulnerabilities.
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