NetScaler | Breaking Cybersecurity News | The Hacker News

A recently disclosed critical flaw in Citrix NetScaler ADC and Gateway devices is being exploited by threat actors to conduct a credential harvesting campaign. IBM X-Force, which uncovered the activity last month,  said  adversaries exploited "CVE-2023-3519 to attack unpatched NetScaler Gateways to insert a malicious script into the HTML content of the authentication web page to capture user credentials." CVE-2023-3519  (CVSS score: 9.8), addressed by Citrix in July 2023, is a critical code injection vulnerability that could lead to unauthenticated remote code execution. Over the past few months, it has been  heavily   exploited  to  infiltrate vulnerable devices  and gain persistent access for follow-on attacks. In the latest attack chain discovered by IBM X-Force, the operators sent a specially crafted web request to trigger the exploitation of CVE-2023-3519 and deploy a PHP-based web shell. The access afforded by the web shell is subseque...

Unpatched Citrix NetScaler systems exposed to the internet are being targeted by unknown threat actors in what's suspected to be a ransomware attack. Cybersecurity company Sophos is  tracking  the activity cluster under the moniker  STAC4663 . Attack chains involve the exploitation of  CVE-2023-3519 , a critical code injection vulnerability impacting NetScaler ADC and Gateway servers that could facilitate unauthenticated remote code execution. In one intrusion detected in mid-August 2023, the security flaw is said to have been used to conduct a domain-wide attack, including injecting payloads into legitimate executables such as the Windows Update Agent (wuauclt.exe) and the Windows Management Instrumentation Provider Service (wmiprvse.exe). An analysis of the payload is underway. Other notable aspects include the distribution of obfuscated PowerShell scripts, PHP web shells, and the use of an Estonian service called BlueVPS for malware staging. Sophos said the...

Vulnerability Management (VM) has long been a cornerstone of organizational cybersecurity. Nearly as old as the discipline of cybersecurity itself, it aims to help organizations identify and address potential security issues before they become serious problems. Yet, in recent years, the limitations of this approach have become increasingly evident.  At its core, Vulnerability Management processes remain essential for identifying and addressing weaknesses. But as time marches on and attack avenues evolve, this approach is beginning to show its age. In a recent report, How to Grow Vulnerability Management into Exposure Management (Gartner, How to Grow Vulnerability Management Into Exposure Management, 8 November 2024, Mitchell Schneider Et Al.), we believe Gartner® addresses this point precisely and demonstrates how organizations can – and must – shift from a vulnerability-centric strategy to a broader Exposure Management (EM) framework. We feel it's more than a worthwhile read an...

Nearly 2,000 Citrix NetScaler instances have been compromised with a backdoor by weaponizing a recently disclosed critical security vulnerability as part of a large-scale attack. "An adversary appears to have exploited CVE-2023-3519 in an automated fashion, placing web shells on vulnerable NetScalers to gain persistent access," NCC Group  said  in an advisory released Tuesday. "The adversary can execute arbitrary commands with this webshell, even when a NetScaler is patched and/or rebooted." CVE-2023-3519 refers to a critical code injection vulnerability impacting NetScaler ADC and Gateway servers that could lead to unauthenticated remote code execution. It was patched by Citrix last month. The development comes a week after the Shadowserver Foundation  said  it identified close to 7,000 vulnerable, unpatched NetScaler ADC and Gateway instances online and the flaw is being abused to drop PHP web shells on vulnerable servers for remote access. A follow-up anal...