CVE-2018-1265 in Diego
Summary
by MITRE
Cloud Foundry Diego, release versions prior to 2.8.0, does not properly sanitize file paths in tar and zip files headers. A remote attacker with CF admin privileges can upload a malicious buildpack that will allow a complete takeover of a Diego Cell VM and access to all apps running on that Diego Cell.
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Analysis
by VulDB Data Team • 02/15/2020
The vulnerability identified as CVE-2018-1265 affects Cloud Foundry Diego components in release versions prior to 2.8.0, representing a critical path traversal flaw that enables arbitrary code execution and system compromise. This vulnerability stems from inadequate input validation within the buildpack processing pipeline, specifically in how the system handles file path information contained within tar and zip archive headers. The flaw operates at the core of Diego's buildpack handling mechanism, where untrusted archive contents are extracted and processed without proper sanitization of path components, creating a pathway for malicious actors to manipulate the extraction process.
The technical implementation of this vulnerability involves the exploitation of weak file path validation during archive extraction operations. When Diego processes buildpack archives, it directly interprets file paths from archive headers without proper sanitization or validation, allowing attackers to craft malicious archive entries with relative path traversal sequences such as ../ or ..\ that can escape the intended extraction directory. This behavior aligns with CWE-22, which categorizes path traversal vulnerabilities as weaknesses in input validation that permit access to restricted directories. The vulnerability is particularly dangerous because it requires only Cloud Foundry administrator privileges to exploit, which is often a privileged role within cloud environments, making it accessible to attackers who have already gained administrative access to the platform.
The operational impact of this vulnerability extends far beyond simple file system manipulation, as it provides complete system compromise of individual Diego Cell VMs. Once exploited, an attacker gains root-level access to the entire cell, enabling them to access and manipulate all applications running within that cell's boundaries. This creates a significant risk for multi-tenant environments where multiple applications share the same infrastructure, as the compromise of one cell can potentially expose data and services from numerous applications. The vulnerability essentially transforms a platform administrator's privileges into full system control, allowing for data exfiltration, service disruption, and potential lateral movement within the cloud infrastructure.
The exploitation of this vulnerability follows a well-defined attack pattern that aligns with ATT&CK framework techniques for privilege escalation and lateral movement. Attackers first leverage their Cloud Foundry administrator credentials to upload a malicious buildpack containing specially crafted archive entries. The system's failure to sanitize these paths during extraction results in the execution of arbitrary code in the context of the Diego cell's privileged process, effectively providing a backdoor into the underlying virtual machine. This attack vector represents a significant risk for organizations using Cloud Foundry as their primary platform for application deployment, as it can lead to complete infrastructure compromise and data breaches.
Organizations should implement immediate mitigations including upgrading to Diego release version 2.8.0 or later, which contains proper path sanitization controls for archive extraction operations. Additional protective measures include implementing strict buildpack validation policies, monitoring for unauthorized buildpack uploads, and establishing network segmentation between Diego cells to limit the impact of potential compromises. The vulnerability also highlights the importance of input validation in containerized environments and demonstrates how seemingly benign archive handling operations can become critical attack vectors when proper sanitization controls are absent. Security teams should also consider implementing automated scanning for malicious archive content and establishing incident response procedures specifically designed for container platform compromises.