CVE-2019-19724 in Singularity
Summary
by MITRE
Insecure permissions (777) are set on $HOME/.singularity when it is newly created by Singularity (version from 3.3.0 to 3.5.1), which could lead to an information leak, and malicious redirection of operations performed against Sylabs cloud services.
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Analysis
by VulDB Data Team • 03/15/2024
The vulnerability described in CVE-2019-19724 represents a critical security flaw in the Singularity containerization platform affecting versions 3.3.0 through 3.5.1. This issue stems from the improper handling of directory permissions during the initialization process of Singularity's home directory structure. When Singularity creates the $HOME/.singularity directory for the first time, it assigns overly permissive 777 permissions, which grants read, write, and execute access to all users on the system. This misconfiguration creates a fundamental security weakness that directly violates the principle of least privilege and establishes a potential attack vector for malicious actors.
The technical flaw manifests as an insecure permissions vulnerability classified under CWE-732, where inadequate permissions are assigned to security-critical resources. The 777 permission setting essentially creates a world-writable directory that can be manipulated by any user on the system, including unprivileged accounts. This misconfiguration allows for information leakage through the exposure of sensitive configuration files, authentication tokens, or cached credentials that might be stored within the .singularity directory. The vulnerability becomes particularly dangerous when considering that Singularity maintains connections with Sylabs cloud services, making the compromised directory a potential conduit for malicious redirection of operations.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential service disruption and unauthorized access to cloud resources. An attacker with access to a system can exploit the world-writable .singularity directory to inject malicious configuration files, modify existing settings, or redirect network traffic to malicious endpoints. This capability directly aligns with ATT&CK technique T1566, which covers credential harvesting through social engineering and manipulation of system resources. The vulnerability undermines the trust model of the containerization platform, as legitimate operations against Sylabs cloud services could be intercepted or redirected by malicious actors who gain control over the compromised directory structure.
The security implications of this vulnerability are particularly severe in multi-user environments where different privilege levels exist, as it creates an attack surface that bypasses normal access controls. The issue affects not only the local system but also introduces risks to cloud service integrations, as any malicious modifications to the .singularity directory could alter how Singularity interacts with external services. Organizations relying on Singularity for containerized applications and scientific computing workloads face significant exposure to unauthorized access patterns and potential data exfiltration. The vulnerability demonstrates a critical failure in the principle of least privilege implementation within the software lifecycle, where security-critical resources are not properly secured during their initial creation phase. Mitigation efforts should focus on immediate permission correction and implementation of proper access control mechanisms, while also emphasizing the importance of secure configuration management in containerization platforms. The vulnerability serves as a reminder of the critical importance of proper permission handling in security-sensitive applications and the potential for seemingly minor configuration errors to create substantial security risks.