Container security firm Prevasio has analyzed 4 million public Docker container images hosted on Docker Hub and discovered that the majority of them had critical vulnerabilities.
The cybersecurity firm used its Prevasio Analyzer service that ran for one month on 800 machines.
51% of the 4 million images were including packages or app dependencies with at least one critical flaw and 13% had high-severity vulnerabilities.
“The dynamic analysis also revealed 6,432 malicious or potentially harmful container images, representing 0.16% of all publicly available images at Docker Hub.” reads the analysis published by Prevasio. “This report explains the work that we’ve done, our findings, the types of malware found and several typical examples of container images found to contain malicious or potentially harmful software.”
Researchers who focused on Linux container images only, revealed that nearly 1% of all images were excluded from the analysis because are built for Windows only and/or have no Linux-specific builds.
The researchers also discovered that 6,432 images included potentially malicious software, such as cryptocurrency miners (44%, 2,842 images and Pull count: 129.5M), hacking tools (20%, 1,269 images and Pull count: 70M), the malicious npm package flatmap-stream (23%, 1,482 images, Pull count: 95M), and tainted applications (trojanized WordPress plugins, Apache Tomcat, and Jenkins).
The total pull count of the malicious or potentially harmful images is over 300 million.
Some of the images contained dynamic payloads that at runtime were downloading the source code of a cryptocurrency miner and execute it.
Experts pointed out that currently, most of the malware found in the images targets Windows.
“The investigation conducted by Prevasio illustrates that Linux OS, and Linux containers in particular are not immune to security risks” concludes the report. “Our research shows that the primary security risk is enabled by critical vulnerabilities. More than half of all container images hosted by Docker Hub, contain one or more critical vulnerability, and are, therefore, potentially exploitable.Another risk is in the fact that out of 4 million publicly available images, 6,432 are found to contain malicious or potentially harmful code.”
(SecurityAffairs – hacking, Docker)