Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Cloud Security

Hard-Coded Credentials Found in Alpine Linux Docker Images

For the past three years, Alpine Linux Docker images have been shipped with a NULL password for the root user, Cisco’s Talos security researchers have discovered. 

For the past three years, Alpine Linux Docker images have been shipped with a NULL password for the root user, Cisco’s Talos security researchers have discovered. 

The hard-coded credentials were included in the Official Alpine Linux Docker images since v3.3, as part of a regression introduced in December 2015. 

Featuring a CVSS score of 9.8, this Critical vulnerability was found to impact Alpine Docker versions 3.3 to 3.9, as well as Alpine Docker Edge. 

The issue is that, in the affected builds of the Alpine Docker Image, the /etc/shadow file contains a blank field instead of the encrypted password. This means that the system treats the root user as having no password. 

“Due to the nature of this issue, systems deployed using affected versions of the Alpine Linux container that utilize Linux PAM, or some other mechanism that uses the system shadow file as an authentication database, may accept a NULL password for the root user,” Talos explains

The vulnerability was first spotted in 2015. However, about a week after it was patched, a commit was pushed to simplify the regression tests. The commit removed the ‘disable root by default’ flag from the ‘edge’ build properties file, thus reintroducing the very same flaw to subsequent builds.

With the default build options appearing to have been copied from this properties file, the flaw has been missing from all tagged builds since December 2015.

Talos reported the vulnerability to the vendor in February. Several days later, it was discovered that the issue was made public on the Alpine Linux’s Github before, although it was not flagged as a security issue and remained unresolved. 

Advertisement. Scroll to continue reading.

The researchers also point out that the root account should be explicitly disabled in Docker images that are based on the affected versions. 

“The likelihood of exploitation of this vulnerability is environment-dependent, as successful exploitation requires that an exposed service or application utilise Linux PAM, or some other mechanism which uses the system shadow file as an authentication database,” Talos notes. 

Related: Container Escape Flaw Hits AWS, Google Cloud, Linux Distros

Related: Code Execution in Alpine Linux Impacts Containers

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join the session as we discuss the challenges and best practices for cybersecurity leaders managing cloud identities.

Register

SecurityWeek’s Ransomware Resilience and Recovery Summit helps businesses to plan, prepare, and recover from a ransomware incident.

Register

Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

CISO Conversations

SecurityWeek talks to Billy Spears, CISO at Teradata (a multi-cloud analytics provider), and Lea Kissner, CISO at cloud security firm Lacework.

Cloud Security

Cloud security researcher warns that stolen Microsoft signing key was more powerful and not limited to Outlook.com and Exchange Online.

CISO Strategy

Okta is blaming the recent hack of its support system on an employee who logged into a personal Google account on a company-managed laptop.

Application Security

Virtualization technology giant VMware on Tuesday shipped urgent updates to fix a trio of security problems in multiple software products, including a virtual machine...

Application Security

Fortinet on Monday issued an emergency patch to cover a severe vulnerability in its FortiOS SSL-VPN product, warning that hackers have already exploited the...

Application Security

A CSRF vulnerability in the source control management (SCM) service Kudu could be exploited to achieve remote code execution in multiple Azure services.

Cloud Security

Microsoft and Proofpoint are warning organizations that use cloud services about a recent consent phishing attack that abused Microsoft’s ‘verified publisher’ status.