CVE-2016-0761 in Cloud Foundry Elastic Runtime
Summary
by MITRE
Cloud Foundry Garden-Linux versions prior to v0.333.0 and Elastic Runtime 1.6.x version prior to 1.6.17 contain a flaw in managing container files during Docker image preparation that could be used to delete, corrupt or overwrite host files and directories, including other container filesystems on the host.
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Analysis
by VulDB Data Team • 10/03/2020
The vulnerability identified as CVE-2016-0761 represents a critical container escape flaw affecting Cloud Foundry Garden-Linux and Elastic Runtime components. This issue stems from improper file system management during Docker image preparation processes within the container orchestration environment. The flaw exists in versions prior to v0.333.0 for Garden-Linux and 1.6.17 for Elastic Runtime, creating a significant security risk that allows malicious actors to gain unauthorized access to host file systems. The vulnerability operates through a privilege escalation mechanism that bypasses container isolation boundaries, effectively undermining the fundamental security model of containerized environments.
The technical implementation of this vulnerability involves a flaw in how container file systems are handled during image preparation phases. When Docker images are processed, the system fails to properly validate or sanitize file paths that are being manipulated or copied between container and host environments. This misconfiguration allows for path traversal attacks that can target not only the current container's file system but also access and modify other containers' filesystems on the same host. The flaw specifically impacts the way temporary files and directories are managed during container creation and image preparation, creating opportunities for arbitrary file system operations.
From an operational impact perspective, this vulnerability exposes organizations to severe data compromise scenarios including unauthorized file deletion, data corruption, and potential system takeover. Attackers could leverage this flaw to overwrite critical system files, delete container data, or even access sensitive information stored in other containers on the same host. The cross-container file system access capability means that a compromised container could potentially affect the entire host infrastructure, leading to cascading security failures. This vulnerability directly undermines the security isolation that containers are designed to provide, making it particularly dangerous in multi-tenant environments where multiple applications share the same infrastructure.
The vulnerability aligns with CWE-22 Path Traversal and CWE-73 Path Traversal in the Common Weakness Enumeration catalog, specifically addressing improper input validation during file system operations. From an attack framework perspective, this flaw maps to multiple ATT&CK techniques including privilege escalation through container escape and persistence mechanisms. Organizations should implement immediate mitigations including upgrading to patched versions of both Garden-Linux and Elastic Runtime components. Additional protective measures include implementing strict container image validation, monitoring for unusual file system access patterns, and employing network segmentation to limit potential lateral movement. The remediation process must include comprehensive testing of the updated components to ensure no regression in functionality while maintaining the security improvements.