Ethical Hacking News
Citrix has issued a warning about a critical vulnerability in their NetScaler appliance that is being actively exploited in denial-of-service (DoS) attacks. The vulnerability affects multiple versions of the NetScaler ADC and Gateway appliances and can be triggered by unauthenticated, remote requests. Administrators are advised to apply patches as soon as possible and implement additional security measures to protect against future attacks.
Citrix has issued a warning about a critical vulnerability in their NetScaler appliance.The vulnerability (CVE-2025-6543) causes denial-of-service (DoS) attacks, bringing devices to a halt.Affected devices can be triggered by unauthenticated, remote requests.Patches are available for affected versions of the appliances.Citrix is urging administrators to patch their devices and implement additional security measures.
Citrix, a leading provider of software solutions for remote access and virtualization, has issued a warning about a critical vulnerability in their popular NetScaler appliance that is being actively exploited in denial-of-service (DoS) attacks. The vulnerability, tracked as CVE-2025-6543, affects multiple versions of the NetScaler ADC and NetScaler Gateway appliances, which are commonly used for secure access to web applications and other resources over the internet.
According to Citrix's advisory, exploits of this vulnerability have been observed in the wild, causing devices to enter a denial-of-service condition. This means that when an attacker sends a malicious request to a NetScaler appliance, it will become unresponsive and unable to process any further requests, effectively bringing down the entire system. The company has warned that affected devices can be triggered by unauthenticated, remote requests.
The vulnerability impacts several versions of the NetScaler ADC and Gateway appliances, including:
* NetScaler ADC versions 14.1 before 14.1-47.46
* NetScaler Gateway versions 13.1 before 13.1-59.19
* NetScaler ADC 13.1-FIPS and NDcPP versions before 13.1-37.236-FIPS and NDcPP
These appliances are configured as Gateways, which provide secure access to web applications, ICA Proxy, Clientless VPN (CVPN), RDP Proxy, or AAA virtual servers.
Citrix has released patches for these vulnerable versions of the NetScaler appliances, including 14.1-47.46, 13.1-59.19, and ADC 13.1-FIPS and NDcPP 13.1-37.236 and later releases of 13.1-FIPS and 13.1-NDcPP. However, it is essential for administrators to apply these patches as soon as possible to prevent further exploitation.
This vulnerability is the latest in a series of critical bugs affecting Citrix products, including the recently disclosed "CitrixBleed" 2 bug (CVE-2025-5777), which allows attackers to hijack user sessions by extracting session tokens from a device's memory. This bug has been used by ransomware gangs and governments in the past to gain unauthorized access to NetScaler devices and move laterally across corporate environments.
In light of these two critical vulnerabilities, Citrix is urging administrators to take immediate action to patch their devices and implement additional security measures to protect against future attacks. This includes monitoring NetScaler instances for unusual user sessions, abnormal behavior, and reviewing access controls.
The rise of such vulnerabilities highlights the importance of proactive security measures in today's increasingly complex and interconnected IT environments. As technology continues to evolve at a rapid pace, it is crucial that administrators prioritize patch management, implement robust security protocols, and stay informed about emerging threats and vulnerabilities.
By staying vigilant and taking swift action against these newly disclosed vulnerabilities, organizations can minimize the risk of data breaches, protect their sensitive information, and maintain the integrity of their IT infrastructure.
Related Information:
https://www.ethicalhackingnews.com/articles/Citrix-Alarms-NetScaler-Vulnerability-Leaves-Devices-Open-to-Denial-of-Service-Attacks-ehn.shtml
https://www.bleepingcomputer.com/news/security/citrix-warns-of-netscaler-vulnerability-exploited-in-dos-attacks/
https://nvd.nist.gov/vuln/detail/CVE-2025-6543
https://www.cvedetails.com/cve/CVE-2025-6543/
https://nvd.nist.gov/vuln/detail/CVE-2025-5777
https://www.cvedetails.com/cve/CVE-2025-5777/
Published: Wed Jun 25 13:20:31 2025 by llama3.2 3B Q4_K_M
