Headline
Citrix NetScaler ADC and Gateway Devices Under Attack: CISA Urges Immediate Action
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) issued an advisory on Thursday warning that the newly disclosed critical security flaw in Citrix NetScaler Application Delivery Controller (ADC) and Gateway devices is being abused to drop web shells on vulnerable systems. "In June 2023, threat actors exploited this vulnerability as a zero-day to drop a web shell on a critical
Vulnerability / Cyber Threat
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) issued an advisory on Thursday warning that the newly disclosed critical security flaw in Citrix NetScaler Application Delivery Controller (ADC) and Gateway devices is being abused to drop web shells on vulnerable systems.
“In June 2023, threat actors exploited this vulnerability as a zero-day to drop a web shell on a critical infrastructure organization’s non-production environment NetScaler ADC appliance,” the agency said.
“The web shell enabled the actors to perform discovery on the victim’s active directory (AD) and collect and exfiltrate AD data. The actors attempted to move laterally to a domain controller but network segmentation controls for the appliance blocked movement.”
The shortcoming in question is CVE-2023-3519 (CVSS score: 9.8), a code injection bug that could result in unauthenticated remote code execution. Citrix, earlier this week, released patches for the issue and warned of active in-the-wild exploitation.
Successful exploitation requires the appliance to be configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or authentication, authorization, and auditing (AAA) virtual server.
CISA did not disclose the name of the organization that was impacted by the incident. The threat actor or the country allegedly behind it is presently unknown.
In the incident analyzed by CISA, the web shell is said to have enabled the collection of NetScaler configuration files, NetScaler decryption keys, and AD information, after which the data was transmitted as a PNG image file (“medialogininit.png”).
UPCOMING WEBINAR
Shield Against Insider Threats: Master SaaS Security Posture Management
Worried about insider threats? We’ve got you covered! Join this webinar to explore practical strategies and the secrets of proactive security with SaaS Security Posture Management.
Join Today
The adversary’s subsequent attempts to laterally move across the network as well as run commands to identify accessible targets and verify outbound network connectivity were thwarted due to robust network segmentation practices, the agency noted, adding the actors also attempted to delete their artifacts to cover up the tracks.
Vulnerabilities in gateway products such as NetScaler ADC and NetScaler Gateway have become popular targets for threat actors looking to obtain privileged access to targeted networks. This makes it imperative that users move quickly to apply the latest fixes to secure against potential threats.
Found this article interesting? Follow us on Twitter and LinkedIn to read more exclusive content we post.
Related news
Threat actors linked to the RansomHub ransomware group encrypted and exfiltrated data from at least 210 victims since its inception in February 2024, the U.S. government said. The victims span various sectors, including water and wastewater, information technology, government services and facilities, healthcare and public health, emergency services, food and agriculture, financial services,
U.S. cybersecurity and intelligence agencies have called out an Iranian hacking group for breaching multiple organizations across the country and coordinating with affiliates to deliver ransomware. The activity has been linked to a threat actor dubbed Pioneer Kitten, which is also known as Fox Kitten, Lemon Sandstorm (formerly Rubidium), Parisite, and UNC757, which it described as connected to
Citrix is warning of two zero-day security vulnerabilities in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway) that are being actively exploited in the wild. The flaws are listed below - CVE-2023-6548 (CVSS score: 5.5) - Authenticated (low privileged) remote code execution on Management Interface (requires access to NSIP, CLIP, or SNIP with management
The latest threat to Citrix NetScaler, CVE-2023-4966, was exploited as a zero-day bug for months before a patch was issued. Researchers expect exploitation efforts to surge.
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
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
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added a critical security flaw in Citrix ShareFile storage zones controller to its Known Exploited Vulnerabilities (KEV) catalog, based on evidence of active in-the-wild exploitation. Tracked as CVE-2023-24489 (CVSS score: 9.8), the shortcoming has been described as an improper access control bug that, if successfully exploited
Categories: Exploits and vulnerabilities Categories: News Tags: Citrix Tags: NetScalers Tags: Germany Tags: CVE-2023-3519 Tags: Fox-IT Tags: DIVD Researchers have found almost 2000 backdoored Citrix NetScalers, many of which were patched after the backdoor in the form of a web shell was dropped. (Read more...) The post Citrix NetScalers backdoored in widespread exploitation campaign appeared first on Malwarebytes Labs.
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
A vulnerability exists within Citrix ADC that allows an unauthenticated attacker to trigger a stack buffer overflow of the nsppe process by making a specially crafted HTTP GET request. Successful exploitation results in remote code execution as root.
Hundreds of Citrix NetScaler ADC and Gateway servers have been breached by malicious actors to deploy web shells, according to the Shadowserver Foundation. The non-profit said the attacks take advantage of CVE-2023-3519, a critical code injection vulnerability that could lead to unauthenticated remote code execution. The flaw, patched by Citrix last month, carries a CVSS score of 9.8. The
Plus: Mozilla fixes two high-severity bugs in Firefox, Citrix fixes a flaw that was used to attack a US-based critical infrastructure organization, and Oracle patches over 500 vulnerabilities.
Categories: Exploits and vulnerabilities Categories: News Tags: Citrix Tags: NetScaler Tags: CVE-2023-3519 Tags: web shell A critical unauthenticated remote code execution vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway is being actively exploited (Read more...) The post CISA: You've got two weeks to patch Citrix NetScaler vulnerability CVE-2023-3519 appeared first on Malwarebytes Labs.
Unauthenticated remote code execution
Citrix is alerting users of a critical security flaw in NetScaler Application Delivery Controller (ADC) and Gateway that it said is being actively exploited in the wild. Tracked as CVE-2023-3519 (CVSS score: 9.8), the issue relates to a case of code injection that could result in unauthenticated remote code execution. It impacts the following versions - NetScaler ADC and NetScaler Gateway 13.1