Kinsing Actors Exploiting Recent Linux Flaw to Breach Cloud Environments
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2017-9841 | Unauthenticated Remote Code Execution in PHPUnit eval-stdin.php PHPUnit ships a utility script (eval-stdin.php under /vendor/phpunit/phpunit/src/Util/PHP/) that reads HTTP POST data and evaluates it as PHP code with no authentication. The flaw is triggered when a site's /vendor folder is web-accessible and an attacker sends a POST request whose body begins with '<?php ' directly to that URI. Doing so lets the attacker execute arbitrary PHP code on the server under the web server account, giving unauthenticated remote code execution (CWE-94 code injection). Anyone running a PHP application installed with Composer, where PHPUnit is present in the vendor tree and that directory is reachable over HTTP, is affected. The flaw is under active exploitation: CISA added it to the Known Exploited Vulnerabilities catalog on 2022-02-15 and its EPSS probability of exploitation is 100% (top percentile). Do: Apply the CISA KEV required action by updating PHPUnit per vendor instructions, which in practice means updating the CMS/framework or running a Composer update that pulls a patched PHPUnit release. Until patched, block web access to the /vendor directory (e.g., deny /vendor/ or at least /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php in your web server configuration) and verify the endpoint is no longer reachable. Check access logs for POST requests to eval-stdin.php and investigate affected servers for webshells or other signs of compromise. | 9.8 | 100% | KEV |
| masshundreds of thousands of PHP sites/servers potentially exposed (order-of-magnitude estimate; unknown precise count) | |
| CVE-2023-32315 | Unauthenticated Path Traversal in Ignite Realtime Openfire Admin Console CVE-2023-32315 is an unauthenticated path traversal flaw (CWE-22) in the Ignite Realtime Openfire XMPP server that allows a remote attacker to reach pages of the Openfire Admin Console that are reserved for administrative users. It is triggered by sending a crafted HTTP request to the admin console web interface containing path traversal sequences, which bypasses the authentication check protecting those restricted pages. Successful exploitation exposes administrative console functionality to an unauthenticated attacker, potentially enabling further compromise of the server and the chat environment it hosts. Any organization running Openfire is affected, particularly instances whose admin console interface is reachable from the internet. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2023-08-24 and carries an EPSS probability of 100% (top percentile), indicating active exploitation in the wild; ransomware use is not yet documented. Do: Upgrade Openfire to the patched release recommended in the Ignite Realtime advisory for CVE-2023-32315, per the CISA KEV required action; if patching must be delayed, restrict the admin console (default ports 9090/9091) to trusted networks or place it behind a VPN. Review access logs for requests to admin console pages containing traversal sequences, and check for unauthorized admin accounts or configuration changes, since KEV listing confirms exploitation in the wild. | 7.5 | 100% | KEV PoC ×2 |
| large≈ tens of thousands of internet-exposed Openfire servers (~30,000–40,000 per public scans) | |
| CVE-2023-4911 | Buffer Overflow in GNU C Library ld.so Grants Root via SUID Binaries CVE-2023-4911 ('Looney Tunables') is a buffer overflow in the GNU C Library's dynamic loader (ld.so) that occurs while processing the GLIBC_TUNABLES environment variable. A local attacker triggers it by launching a set-user-ID (SUID) binary with a maliciously crafted GLIBC_TUNABLES value, corrupting memory in the privileged process. This allows the attacker to execute code with elevated (root) privileges on the host. Any system running an affected glibc is potentially exposed, including major Linux distributions (Fedora, Red Hat, Canonical, Debian), Red Hat CodeReady Linux Builder channels, NetApp products, and Siemens SIMATIC S7-1500 firmware, although exploitation requires local execution capability or a foothold on the machine. Exploitation is confirmed in the wild: Qualys published a working proof-of-concept, the flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2023-11-21, and Kinsing threat actors have used it for cryptojacking and to breach cloud environments. Do: Install patched glibc updates from your distribution vendor (Fedora, Red Hat, Canonical/Ubuntu, Debian) and apply Siemens firmware updates for affected SIMATIC S7-1500 MFP devices; NetApp customers should follow NetApp's remediation guidance. Until patched, audit SUID/SGID binaries (which the attacker needs as the escalation trigger) and limit untrusted local access and shell access on multi-user or cloud-hosted Linux systems. Per the CISA KEV required action, apply vendor mitigations or discontinue use, prioritizing internet-facing hosts given active Kinsing cryptojacking and cloud-breach activity. | 7.8 | 81% | KEV PoC ×6 |
| masshundreds of millions of Linux installations worldwide (glibc is the standard C library shipped with virtually every major distribution) |
Full article390 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananNov 03, 2023Cloud Security / Linux
The threat actors linked to Kinsing have been observed attempting to exploit the recently disclosed Linux privilege escalation flaw called Looney Tunables as part of a "new experimental campaign" designed to breach cloud environments.
"Intriguingly, the attacker is also broadening the horizons of their cloud-native attacks by extracting credentials from the Cloud Service Provider (CSP)," cloud security firm Aqua said in a report shared with The Hacker News.
The development marks the first publicly documented instance of active exploitation of Looney Tunables (CVE-2023-4911), which could allow a threat actor to gain root privileges.
Kinsing actors have a track record of opportunistically and swiftly adapting their attack chains to exploit newly disclosed security flaws to their advantage, having most recently weaponized a high-severity bug in Openfire (CVE-2023-32315) to achieve remote code execution.
The latest set of attacks entails exploiting a critical remote code execution shortcoming in PHPUnit (CVE-2017-9841), a tactic known to be employed by the cryptojacking group since at least 2021, to obtain initial access.
This is followed by manually probing the victim environment for Looney Tunables using a Python-based exploit published by a researcher who goes by the alias bl4sty on X (formerly Twitter).
"Subsequently, Kinsing fetches and executes an additional PHP exploit," Aqua said. "Initially, the exploit is obscured; however, upon de-obfuscation, it reveals itself to be a JavaScript designed for further exploitative activities."
The JavaScript code, for its part, is a web shell that grants backdoor access to the server, enabling the adversary to perform file management, command execution, and gather more information about the machine it's running on.
The end goal of the attack appears to be to extract credentials associated with the cloud service provider for follow-on actions, a significant tactical shift from the threat actor's pattern of deploying the Kinsing malware and launching a cryptocurrency miner.
"This marks the inaugural instance of Kinsing actively seeking to gather such information," security researcher Assaf Morag said.
"This recent development suggests a potential broadening of their operational scope, signaling that the Kinsing operation may diversify and intensify in the near future, thereby posing an increased threat to cloud-native environments."
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