Atlassian has issued a security advisory on a severe unpatched remote code execution vulnerability that affects Confluence Server and Data Center products and is being actively abused in the field, according to the company. The CVE-2022-26134 vulnerability was found as an extensively exploited zero-day towards the end of May, and the vendor issued a patch on June 3, 2022.
Several proof-of-concept (PoC) exploits for the CVE-2022-26134 bug have been made public.
Following the disclosure of the RCE, Check Point Research (CPR) researchers observed a large number of exploitation attempts, with some of the malicious payloads used in the attacks being used as part of the same campaign carried by a crypto mining gang known as the "8220 gang" by doing bulk net scans to discover vulnerable Windows and Linux endpoints to plant miners.
Miners are special-purpose programs that mine cryptocurrency like Monero for the threat actor using the host's available computational capabilities. Reduced server performance, increase hardware wear, greater operating costs, and even business disruption are all direct consequences of this action. These actors can also improve their attack at any time and dump more potent payloads because they have access to the system.
Multiple infection chains are used to target Linux and Windows operating systems.
The attack starts with a specially crafted HTTP request which exploits CVE-2022-26134 and dumps a base64-encoded payload on both Linux and Windows platforms. The payload then downloads an executable, a Linux malware injects script and a Windows child process spawner. Both scenarios try to set up reboot persistence, then delete all current devices before activating the miner.
The miner will deplete all system resources in both circumstances, therefore the "8220 gang" is aiming for maximum profit until the malware is uprooted, rather than silently mining on infected servers and attempting to remain undiscovered by using only a portion of the available processing capacity. Eventually, the Linux script looks for SSH keys on the host in an attempt to expand to other computers nearby.
The web shell is believed to have been used to distribute two further web shells to disk, namely China Chopper and a bespoke file upload shell for exfiltrating arbitrary files to a remote server. The news comes within a year of another severe remote code execution issue in Atlassian Confluence (CVE-2021-26084, CVSS score: 9.8) was actively exploited in the open to install cryptocurrency miners on compromised servers (CVE-2021-26084, CVSS score: 9.8).
"Attackers can get direct access to highly valuable systems by exploiting such type of vulnerability," Volexity stated. "Furthermore, because they lack the necessary monitoring or logging capabilities, these systems can be difficult to investigate."
