CVE-2025-0526 in Octopus Server
Summary
by MITRE • 02/11/2025
In affected versions of Octopus Deploy it was possible to upload files to unexpected locations on the host using an API endpoint. The field lacked validation which could potentially result in ways to circumvent expected workflows.
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Analysis
by VulDB Data Team • 07/02/2025
The vulnerability identified as CVE-2025-0526 represents a critical file system exposure issue within Octopus Deploy software versions that allows unauthorized file upload operations to arbitrary locations on the host system. This flaw stems from insufficient input validation within a specific API endpoint that handles file upload functionality. The absence of proper sanitization and validation mechanisms enables malicious actors to manipulate the upload process and potentially place files in directories outside the intended scope of the application's file handling capabilities.
This security weakness operates through a classic path traversal or directory traversal attack vector where the vulnerable API endpoint accepts user-supplied data without adequate verification of the target file path. The flaw creates an environment where an attacker can manipulate the upload destination by including directory traversal sequences or by directly specifying alternative file paths within the upload request. Such behavior fundamentally violates the principle of least privilege and allows for arbitrary file placement on the host system, potentially leading to further exploitation opportunities.
The operational impact of CVE-2025-0526 extends beyond simple unauthorized file uploads, as it can enable attackers to place malicious files in critical system directories or locations where they might be executed by the application or system processes. This vulnerability could potentially allow for privilege escalation, persistence mechanisms, or the execution of arbitrary code depending on the system configuration and the permissions of the Octopus Deploy service account. The issue particularly affects environments where Octopus Deploy is used for deployment automation, as it undermines the integrity of the deployment pipeline and could compromise the entire infrastructure.
From a cybersecurity perspective, this vulnerability aligns with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory and CWE-73 - External Control of File Name or Path, both of which are fundamental weaknesses in file system access control. The attack pattern follows typical TTPs from the MITRE ATT&CK framework under TA0005 - Defense Evasion and TA0004 - Privilege Escalation, where adversaries seek to manipulate file system operations to establish persistence or elevate privileges. Organizations using affected Octopus Deploy versions should immediately implement mitigation measures including input validation, path sanitization, and restricted file upload permissions.
The recommended remediation approach involves implementing comprehensive input validation on all file upload endpoints, including strict path validation and normalization to prevent directory traversal attacks. System administrators should also review and restrict the file system permissions for the Octopus Deploy service account to minimize potential damage from successful exploitation attempts. Additionally, network segmentation and monitoring of API endpoint access patterns can help detect anomalous file upload activities that might indicate exploitation attempts. Organizations should also consider implementing web application firewalls and regular security assessments to identify similar vulnerabilities in their deployment automation tools.