Hackers Actively Exploited Ivanti 0-Day to Execute Arbitrary Commands

Invati Connect Secure (ICS) and Ivanti Policy Secure Gateways have been discovered with two new vulnerabilities associated with authentication bypass and command injection.

The CVEs for these vulnerabilities have been assigned as CVE-2023-46805 and CVE-2024-21887. The severity of these vulnerabilities has been given as 8.2 (High) and 9.1 (Critical), respectively.

However, Ivanti has released a security advisory to address these vulnerabilities along with the patched version of the products.

It was also mentioned that Ivanti neurons for ZTA gateways cannot be exploited in production. UTA0178 actively exploited these vulnerabilities.

Exploitation in the Wild

According to the reports shared with Cyber Security News, a threat actor actively exploited these two vulnerabilities to steal configuration data, download remote files, and create a reverse tunnel from the ICS VPN appliance.

Moreover, the threat actor made several changes to the system to evade the ICS integrity checker tool. 

In addition, the threat actor backdoored a legitimate CGI file on the ICS VPN appliance to enable command execution over the compromised system.

The attacker also modified the Web SSL VPN JavaScript file to keylog and extract users’ login credentials.

Courses of the Incident

A curl command was for outbound connections to an IP Geolocation service through ip-api[.]com to Cloudflare’s 1.1.1.1 IP address. Additionally, reverse SOCKS proxy and SSH connections were established and downloaded from compromised Cyberoam appliances. 

Lateral movements were also noticed through compromised credentials to connect to internal systems through RDP, SMB, and SSH. Furthermore, there was also the transfer of multiple webshell variants, termed as “GLASSTOKEN”, to Internet-accessible web servers and systems that were only internally accessible.

The attacker created and executed several files from the system’s /tmp/ directory, which were no longer on disk at the time of analysis. A list of the following paths was excluded on the list of Integrity Checker Tool,

• /tmp/rev
• /tmp/s.py
• /tmp/s.jar
• /tmp/b
• /tmp/kill

During the course of the incident, Volexity distributed a few malicious files and tools, the most of which comprised of webshells, proxy utilities, and file alterations that allowed credential harvesting. This was despite the fact that Volexity observed the attacker practically living off the land for the most part.

• In numerous instances, the attacker used compromising credentials to enter onto workstations and servers and dump LSASS process memory to disk via Task Manager.
• The attacker extracted further credentials offline by exfiltrating this output.
• The attacker accessed a system with Virtual Hard Disk backups, including a domain controller backup. After mounting this virtual hard disk, they extracted the Active Directory database ntds.dit file and compressed it using 7-Zip.
• The attacker found a running Veeam backup software instance and used a GitHub script to steal passwords.
• As said, the attacker updated JavaScript on the ICS VPN Appliance’s Web SSL VPN login page to steal credentials.

A complete report about this incident has been published, providing detailed information about the threat actor’s activities, webshell information, and others.

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