Quick update on #CitrixBleed - tracking just over 20k exploited Netscaler servers so far today, where session tokens have been stolen.
How? Have a honeypot running to gather data on attackers, then compare with Netflow via industry friends. Two TCP connections (first large) plus Shodan cross reference to validate Netscaler victim.
Also it turns out in March of this year somebody documented how to replay the session token to bypass MFA/login: https://www.vulnerability-db.com/?q=articles/2023/07/03/citrix-gateway-cloud-mfa-insufficient-session-validation-vulnerability