Urgent Advisory - LockBit 3.0 Ransomware Exploits 'Citrix Bleed' Vulnerability

Joint Cybersecurity Advisory Warns of LockBit 3.0 Ransomware Exploiting Critical 'Citrix Bleed' Vulnerability

In a crucial cybersecurity collaboration, the Cybersecurity and Infrastructure Security Agency (CISA), FBI, MS-ISAC, and ASD’s ACSC have issued a joint advisory about LockBit 3.0 ransomware exploiting the CVE-2023-4966 vulnerability, known as "Citrix Bleed." This vulnerability affects Citrix NetScaler ADC and Gateway appliances.

CVE-2023-4966 and CVE-2023-4967 | Lockbit 3.0 'Citrix Bleed' VulnerabilityMultiple Vulnerabilities Have Been Discovered In NetScaler ADC (Formerly Citrix ADC) And NetScaler Gateway (Formerly Citrix Gateway).Critical Vulnerability

The advisory details TTPs and IOCs sourced from the FBI, ACSC, and Boeing. Boeing's experience with LockBit 3.0 exploiting CVE-2023-4966 for unauthorised access highlights the threat's seriousness. LockBit 3.0, known for its diverse attack methods, targets multiple critical infrastructure sectors. "Citrix Bleed" allows attackers to bypass passwords and MFA, facilitating unauthorised access and data compromise.

CISA and partnering organisations stress the urgency of applying the recommended mitigations, including isolating affected appliances and updating software via the Citrix Knowledge Center. The vulnerability, which enables hijacking legitimate user sessions, was identified in early 2023 and publicly disclosed by Citrix in October 2023. Due to its severity, CISA added it to the KEVs Catalog, emphasising its critical impact on various software versions.

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Analysis of the Advisory's Significance for Businesses

This advisory's release is a significant wake-up call for businesses globally. It underscores the escalating sophistication of cyber threats, particularly ransomware like LockBit 3.0, which now exploit critical vulnerabilities to gain extensive access to corporate networks. The ability to bypass MFA, a cornerstone of modern cybersecurity defences, represents a new level of threat that requires immediate and proactive response. Businesses, especially those in critical infrastructure sectors, must prioritise patching vulnerabilities like CVE-2023-4966 and adopt a layered security approach. This incident highlights the ongoing arms race in cybersecurity, where businesses must constantly evolve their defences in response to increasingly advanced cyber threats.