FlagThis — Daily Cybersecurity Intelligence Briefing

Threat actors are actively exploiting CVE-2023-4966, known as "CitrixBleed," an information disclosure vulnerability in Citrix NetScaler ADC and NetScaler Gateway. By triggering a memory leak, attackers extract sensitive session tokens from the appliance's memory, allowing them to hijack authenticated sessions and completely bypass multi-factor authentication (MFA). This flaw serves as a primary initial access vector for lateral movement and ransomware deployment. Immediate remediation requires applying vendor security patches and terminating all active user sessions to invalidate potentially compromised tokens.