CVE-2020-29601 in Notary Docker Image
Summary
by MITRE • 12/09/2020
The official notary docker images before signer-0.6.1-1 contain a blank password for a root user. System using the notary docker container deployed by affected versions of the docker image may allow an remote attacker to achieve root access with a blank password.
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Analysis
by VulDB Data Team • 12/14/2020
The vulnerability identified as CVE-2020-29601 affects the official notary docker images prior to the signer-0.6.1-1 release, presenting a critical security risk through the use of a blank password for the root user account. This flaw represents a fundamental misconfiguration that directly violates security best practices and creates an exploitable entry point for remote attackers. The notary service, which is designed to provide content trust and signing capabilities for docker images, becomes completely compromised when an attacker can authenticate as the root user without any credential requirements. This vulnerability specifically impacts systems that deploy the notary service using affected docker image versions, creating a persistent security risk for any organization relying on these components for container image verification and signing operations.
The technical flaw manifests as an insecure default configuration where the root user account within the docker container is initialized with an empty password field, allowing any remote attacker to gain immediate root-level access to the system. This represents a clear violation of the principle of least privilege and demonstrates poor security hardening practices during the container image creation process. The vulnerability falls under CWE-798, which specifically addresses the use of hard-coded credentials, and more broadly relates to CWE-259, which covers the use of hard-coded passwords. From an operational perspective, this flaw transforms what should be a secure signing service into a potential attack vector that could compromise the entire container orchestration environment where the notary service is deployed.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to achieve complete system compromise without any authentication challenges or credential guessing attempts. Once an attacker gains root access through the blank password, they can manipulate the notary service to sign malicious containers, potentially compromising the integrity of the entire container image supply chain. This vulnerability directly maps to several ATT&CK techniques including T1078.004 for valid accounts and T1566 for social engineering, though the latter is less applicable given the automated nature of the exploitation. The attack surface extends beyond just the immediate notary service to potentially compromise other systems that trust the notary service for image validation, creating cascading security failures throughout the container ecosystem.
Organizations should immediately update their notary deployments to signer-0.6.1-1 or later versions to address this vulnerability. The recommended mitigation strategy involves not only updating the docker images but also implementing proper access controls, network segmentation, and monitoring for unauthorized access attempts. Security teams should conduct comprehensive audits of all systems using affected notary images to ensure no unauthorized access has occurred. Additionally, organizations should implement automated scanning solutions to detect similar insecure configurations in other container images and establish security policies that prevent the use of images with blank passwords or other hard-coded credentials. The remediation process should include validating that the updated images properly enforce authentication mechanisms and that no other insecure default configurations exist within the deployment environment.