Citrix Bleed: vulnerability in the two-factor authentication system

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Recent weeks have seen considerable turmoil in the cybersecurity space due to a vulnerability that allows two-factor authentication to be bypassed and devices being slow to receive necessary updates. The discovery of Citrix Bleed, a vulnerability that poses a high risk, has led to widespread concern.

Details of the Citrix Bleed vulnerability

Citrix Bleed puts at risk sensitive information, such as session tokens, that are associated with devices after providing the correct login credentials. This allows you to completely bypass the additional layers of security provided by multi-factor authentication systems. The vulnerability, identified by the code CVE-2023-4966, is linked to two Citrix components, the Netscaler Application Delivery Controller and the Netscaler Gateway. Unfortunately, device owners appear to be in no rush to make critical security updates.

Attacks behind Citrix Bleed

According to researcher Kevin Beaumont, the number of attacks exploiting this vulnerability has increased in recent months. Several actors in the hacking field, including groups specializing in ransomware attacks, are massively exploiting this vulnerability. Estimates indicate that over 20,000 devices have suffered access token theft through the Citrix vulnerability. These attacks can be carried out quickly, as demonstrated by research conducted via honeypot servers that tracked 135 IP addresses linked to such attacks.

Citrix Bleed and the need for protection

According to cybersecurity experts, it is essential to immediately install the security patch released by Citrix to protect your devices. Devices that have not yet been updated are considered compromised and all corporate login credentials should be changed to prevent session token theft. This is reminiscent of the case of Heartbleed, a similar vulnerability that caused panic in 2014. Despite the risk, most ordinary users may not be affected, unless they work in companies or companies that operate in cloud or data centers.