Apache ActiveMQ Flaw Exploited to Deploy DripDropper Malware on Cloud Linux Systems
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2023-46604 | Unauthenticated RCE in Apache ActiveMQ via OpenWire Deserialization CVE-2023-46604 is a critical deserialization flaw (CWE-502) in the Java OpenWire protocol marshaller of Apache ActiveMQ that permits unauthenticated remote code execution (CVSS 9.8). An attacker with network access to either a Java-based OpenWire broker or client can manipulate serialized class types in the OpenWire protocol, causing the peer to instantiate arbitrary classes on the classpath and execute arbitrary shell commands. Successful exploitation yields full command execution on the target broker or client, with no authentication or user interaction required. Affected parties include anyone running ActiveMQ broker or Java client versions prior to 5.15.16, 5.16.7, 5.17.6, or 5.18.3, as well as NetApp E-Series products and Debian packages that ship affected ActiveMQ/OpenWire components. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2023-11-02 with known ransomware use (RansomHub), and has been used to drop Kinsing malware, Godzilla web shells, and the DripDropper implant, in some cases with attackers patching the flaw post-exploitation to lock out competing intruders. Do: Upgrade all ActiveMQ brokers and Java OpenWire clients to 5.15.16, 5.16.7, 5.17.6, or 5.18.3 (or later), and apply the relevant NetApp E-Series and Debian updates for bundled components; restrict the OpenWire port (default TCP 61616) from untrusted networks. Hunt for indicators of the documented campaigns (Godzilla web shells, Kinsing malware, DripDropper, RansomHub) and verify the broker's current version, since attackers have been observed patching the flaw post-exploitation to hide from defenders. The CISA KEV listing means federal agencies must apply vendor mitigations or discontinue use of the product. | 9.8 | 100% | KEV ransomware PoC |
| largetens of thousands of internet-exposed OpenWire brokers (order of 10,000–100,000 by public scans), plus uncounted internal deployments and bundled NetApp/Debian… |
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Ravie LakshmananAug 19, 2025Linux / Malware
Threat actors are exploiting a nearly two-year-old security flaw in Apache ActiveMQ to gain persistent access to cloud Linux systems and deploy malware called DripDropper.
But in an unusual twist, the unknown attackers have been observed patching the exploited vulnerability after securing initial access to prevent further exploitation by other adversaries and evade detection, Red Canary said in a report shared with The Hacker News.
"Follow-on adversary command-and-control (C2) tools varied by endpoint and included Sliver, and Cloudflare Tunnels to maintain covert command and control over the long term," researchers Christina Johns, Chris Brook, and Tyler Edmonds said.
The attacks exploit a maximum-severity security flaw in Apache ActiveMQ (CVE-2023-46604, CVSS score: 10.0), a remote code execution vulnerability that could be exploited to run arbitrary shell commands. It was addressed in late October 2023.
The security defect has since come under heavy exploitation, with multiple threat actors leveraging it to deploy a wide range of payloads, including HelloKitty ransomware, Linux rootkits, GoTitan botnet malware, and Godzilla web shell.
In the attack activity detected by Red Canary, the threat actors have been observed leveraging the access to modify existing sshd configurations to enable root login, granting them elevated access to drop a previously unknown downloader dubbed DripDropper.
A PyInstaller Executable and Linkable Format (ELF) binary, DripDropper requires a password to run in a bid to resist analysis. It also communicated with an attacker-controlled Dropbox account, once again illustrating how threat actors are increasingly relying on legitimate services to blend in with regular network activity and sidestep detection.
The downloader ultimately serves as a conduit for two files, one of which facilitates a varied set of actions on different endpoints, ranging from process monitoring to contacting Dropbox for further instructions. Persistence of the dropped file is achieved by modifying the 0anacron file present in /etc/cron.hourly, /etc/cron.daily, /etc/cron.weekly, /etc/cron.monthly directories.
The second file dropped by DripDropper is also designed to contact Dropbox for receiving commands, while also altering existing configuration files related to SSH, likely as a backup mechanism for persistent access. The final stage entails the attacker downloading from Apache Maven patches for CVE-2023-46604, effectively plugging the flaw.
"Patching the vulnerability does not disrupt their operations as they already established other persistence mechanisms for continued access," the researchers said.
While certainly rare, the technique is not new. Last month, France's national cybersecurity agency ANSSI detailed a China-nexus initial access broker employing the same approach to secure access to systems and prevent other threat actors from using the shortcomings to get in and mask the initial access vector used in the first place.
The campaign offers a timely reminder for why organizations need to apply patches in a timely fashion, limit access to internal services by configuring ingress rules to trusted IP addresses or VPNs, and monitor logging for cloud environments to flag anomalous activity.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2025/08/apache-activemq-flaw-exploited-to.html