In a recent development, a critical server-side request forgery (SSRF) vulnerability has been discovered in Ivanti Connect Secure and Ivanti Policy Secure servers, marked as CVE-2024-21893. Security experts have confirmed that this vulnerability is being actively exploited by multiple attackers, raising concerns over the security of affected systems worldwide. 

SSRF vulnerabilities allow attackers to send crafted requests from the vulnerable server, potentially leading to unauthorized access to internal resources, sensitive data exposure, or even full system compromise. Imagine you have a key to open doors in a building. Now, imagine someone tricks you into using that key to open doors you are not supposed to. That is what happens in an SSRF attack. 

Normally, a website can only talk to the outside world through your web browser. But in an SSRF attack, the bad guys make the website talk to other places it is not supposed to, like secret internal parts of a company's network or even random outside websites. This can lead to big problems. 

For example, if the website connects to a secret part of a company's network, the bad guys might steal important information. Or if it connects to a random website, it might give away sensitive data, like your passwords or credit card numbers. 

Ivanti raised the alarm about a critical flaw in the gateway's SAML components on January 31, 2024. This vulnerability, identified as CVE-2024-21893, was immediately classified as a zero-day exploit, indicating that hackers were already taking advantage of it. Initially, the impact seemed limited, affecting only a small number of customers. 

However, the exploitation of CVE-2024-21893 opened the door for attackers to sidestep authentication measures and gain unauthorized access to restricted resources on vulnerable devices, specifically those operating on versions 9.x and 22.x. 

Now, according to the threat monitoring service Shadowserver, the situation has escalated. They have detected numerous attackers capitalizing on the SSRF bug, with a staggering 170 unique IP addresses attempting to exploit the vulnerability. This widespread exploitation poses a significant threat to the security of affected systems and the data they hold. 

The disclosure of CVE-2024-21893 revealed a series of critical vulnerabilities affecting Ivanti Connect Secure and Policy Secure VPN appliances. Alongside CVE-2024-21893, two other zero-day vulnerabilities, CVE-2023-46805 and CVE-2024-21887, were also identified on January 10, 2024, prompting Ivanti to release temporary mitigations. 

These vulnerabilities were exploited by the Chinese espionage threat group UTA0178/UNC5221, resulting in the installation of webshells and backdoors on compromised devices. Despite initial mitigations, attackers managed to bypass defenses, compromising even device configuration files. 

Ivanti postponed firmware patches scheduled for January 22 due to the sophisticated nature of the threat. Given the active exploitation of multiple critical zero-days, the U.S. Cybersecurity & Infrastructure Security Agency (CISA) has mandated federal agencies to disconnect all Ivanti Connect Secure and Policy Secure VPN appliances. 

Only devices that have been factory reset and updated to the latest firmware should be reconnected. However, older versions without a patch remain vulnerable. While this directive is not compulsory for private organizations, they are strongly advised to assess the security status of their Ivanti deployments and overall environment, considering the potential risks posed by these vulnerabilities. 

Ivanti is a company based in Utah, USA, that makes different kinds of computer software for things like keeping your computer safe, managing IT services, tracking IT assets, managing all your devices from one place, controlling who has access to what, and managing the supply chain. It was created in 2017 when two companies, LANDESK and HEAT Software, joined together. Later, they also bought another company called Cherwell Software. Ivanti became more famous because of some big problems with the security of the VPN hardware they sell.