Hackers Targeting Unpatched Atlassian Confluence Servers to Deploy Crypto Miners
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-4034 | Out-of-Bounds Read/Write Local Privilege Escalation in polkit pkexec (PwnKit) CVE-2021-4034 ('PwnKit') is an out-of-bounds read and write (CWE-125/CWE-787) in polkit's setuid-root pkexec utility, which mishandles the calling parameter count and ends up trying to execute environment variables as commands. A local attacker who runs pkexec with crafted environment variables can induce it to execute arbitrary code, gaining administrative (root) rights on the target machine. Because polkit is installed by default on mainstream Linux distributions — including Red Hat Enterprise Linux and its many variants, with the flaw also tracked against Canonical, SUSE, Oracle, Siemens, and StarWind Software products — essentially every standard Linux installation was exposed. The flaw is being actively exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2022-06-27 with known ransomware use, and EPSS assigns a 94.9% probability of exploitation (100th percentile). Public proof-of-concept exploits are widely available, making exploitation trivial for any user with local access to an unpatched host. Do: Apply the polkit/pkexec updates from each distribution vendor immediately per vendor instructions, as required by the CISA KEV catalog. If patching must be delayed, removing the setuid bit from pkexec (e.g., chmod 0755 /usr/bin/pkexec) is a widely documented interim mitigation, though it may affect functionality that relies on pkexec. Prioritize hosts where untrusted or low-privilege users can log in, and hunt for prior exploitation given known ransomware use. | 7.8 | 95% | KEV ransomware PoC ×4 |
| masstens of millions of Linux servers and workstations (polkit/pkexec ships by default on virtually all mainstream distributions) | |
| CVE-2022-26134 | Unauthenticated OGNL Injection RCE in Atlassian Confluence Server/Data Center Atlassian Confluence Server and Data Center contain an unauthenticated remote code execution flaw caused by improper neutralization of expression-language (OGNL) input (CWE-917): an attacker with network access to the application can submit a crafted request that is evaluated as an expression and executed by the server. Successful exploitation lets a remote, unauthenticated attacker run arbitrary code with the privileges of the Confluence process, without any credentials. All organizations running self-managed Confluence Server or Data Center are affected, particularly instances exposed to the internet; Confluence Cloud is not listed among the affected products. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2022-06-02 with ransomware use marked as known, and EPSS assigns a 100% probability of exploitation within 30 days (100th percentile). CVSS has not yet been scored in this data, but the KEV listing and known ransomware use make unpatched, internet-facing instances a top-priority patching target. Do: Immediately upgrade to the patched Confluence release specified in Atlassian's 2022-06-02 security advisory, and until patched follow the CISA required action to block all internet traffic to and from affected instances. Because in-the-wild exploitation and ransomware use are confirmed, also hunt for compromise indicators on both patched and unpatched hosts, such as webshells, unexpected child processes of the Confluence service, and unusual outbound connections. | 9.8 | 100% | KEV ransomware PoC ×2 |
| largetens of thousands of internet-exposed instances (public scan counts of roughly 60,000-90,000 Confluence Server/Data Center hosts around the June 2022… |
Full article352 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananSep 22, 2022
A now-patched critical security flaw affecting Atlassian Confluence Server that came to light a few months ago is being actively exploited for illicit cryptocurrency mining on unpatched installations.
"If left unremedied and successfully exploited, this vulnerability could be used for multiple and more malicious attacks, such as a complete domain takeover of the infrastructure and the deployment information stealers, remote access trojans (RATs), and ransomware," Trend Micro threat researcher Sunil Bharti said in a report.
The issue, tracked as CVE-2022-26134 (CVSS score: 9.8), was addressed by the Australian software company in June 2022.
In one of the infection chains observed by the cybersecurity company, the flaw was leveraged to download and run a shell script ("ro.sh") on the victim's machine, which, in turn, fetched a second shell script ("ap.sh").
The malicious code is designed to update the PATH variable to include additional paths such as "/tmp", download the cURL utility (if not already present) from a remote server, disable iptables firewall, abuse the PwnKit flaw (CVE-2021-4034) to gain root privileges, and ultimately deploy the hezb crypto miner.
Like other cryptojacking attacks, the shell script also terminates other competing coin miners, disables cloud service provider agents from Alibaba and Tencent, before carrying out lateral movement via SSH.
The findings mirror similar exploitation attempts previously disclosed by Lacework, Microsoft, Sophos, and Akamai in June.
Lacework's analysis further shows that the command-and-control (C2) server used to retrieve the cURL software as well as the hezb miner also distributed a Golang-based ELF binary named "kik" that enables the malware to kill processes of interest.
Users are advised to prioritize patching the flaw as it could be abused by threat actors for other nefarious purposes.
"Attackers could take advantage of injecting their own code for interpretation and gain access to the Confluence domain being targeted, as well as conduct attacks ranging from controlling the server for subsequent malicious activities to damaging the infrastructure itself," Bharti said.
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