to data theft , takeover , and cryptocurrency mining attacks . This is because hackers can exploit two vulnerabilities to gain admin rights or log in using invalid credentials on these servers . Both vulnerabilities were discoveredVulnerability-related.DiscoverVulnerabilityby security researchers from CyberArk , were privately reportedVulnerability-related.DiscoverVulnerabilityto the Jenkins team , and receivedVulnerability-related.PatchVulnerabilityfixes over the summer . But despite patches for both issues , there are still thousands of Jenkins servers availableVulnerability-related.PatchVulnerabilityonline . Jenkins is a web application for continuous integration built in Java that allows development teams to run automated tests and commands on code repositories based on test results , and even automate the process of deploying new code to production servers . Jenkins is a popular component in many companies ' IT infrastructure and these servers are very popular with both freelancers and enterprises alike . Over the summer , CyberArk researchers discoveredVulnerability-related.DiscoverVulnerabilitya vulnerability ( tracked asVulnerability-related.DiscoverVulnerabilityCVE-2018-1999001 ) that allows an attacker to provide malformed login credentials that cause Jenkins servers to move their config.xml file from the Jenkins home directory to another location . If an attacker can cause the Jenkins server to crash and restart , or if he waits for the server to restart on its own , the Jenkins server then boots in a default configuration that features no security . In this weakened setup , anyone can register on the Jenkins server and gain administrator access . With an administrator role in hand , an attacker can access private corporate source code , or even make code modifications to plant backdoors in a company 's apps . This lone issue would have been quite bad on its own , but CyberArk researchers also discoveredVulnerability-related.DiscoverVulnerabilitya second Jenkins vulnerability -- CVE-2018-1999043 . This second bug , they saidVulnerability-related.DiscoverVulnerability, allowed an attacker to create ephemeral user records in the server 's memory , allowing an attacker a short period when they could authenticate using ghost usernames and credentials . Both vulnerabilities were fixedVulnerability-related.PatchVulnerability, the first in July and the second in August , but as we 've gotten accustomed to in the past few years of covering security flaws , not all server owners have bothered to install these security updates .