CVE-2017-8907 in Bamboo
Summary
by MITRE
Atlassian Bamboo 5.x before 5.15.7 and 6.x before 6.0.1 did not correctly check if a user creating a deployment project had the edit permission and therefore the rights to do so. An attacker who can login to Bamboo as a user without the edit permission for deployment projects is able to use this vulnerability, provided there is an existing plan with a green build, to create a deployment project and execute arbitrary code on an available Bamboo Agent. By default a local agent is enabled; this means that code execution can occur on the system hosting Bamboo as the user running Bamboo.
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Analysis
by VulDB Data Team • 10/16/2024
The vulnerability described in CVE-2017-8907 represents a critical authorization flaw within Atlassian Bamboo's deployment project management system. This issue affects versions 5.x prior to 5.15.7 and 6.x prior to 6.0.1, where the software fails to properly validate user permissions when creating deployment projects. The flaw stems from inadequate access control mechanisms that allow unauthorized users to bypass the normal permission checks required for deployment project creation. According to CWE-284, this represents an improper access control vulnerability where the system does not properly enforce authorization checks. The vulnerability specifically targets the deployment project creation workflow, which should require explicit edit permissions but instead permits creation by users who lack the necessary privileges.
The technical exploitation of this vulnerability requires an attacker to possess valid login credentials for a Bamboo user account that does not normally have edit permissions for deployment projects. However, the attacker must also have access to an existing build plan that has successfully completed with a green status, indicating that the build is ready for deployment. This prerequisite creates a specific attack vector that leverages the legitimate deployment workflow to execute malicious code. The vulnerability's impact extends beyond simple privilege escalation into full system compromise, as the affected Bamboo server typically runs with local agents enabled by default. This configuration allows the attacker to execute arbitrary code on the same system hosting Bamboo, running with the privileges of the user account running the Bamboo service.
The operational impact of this vulnerability is severe and can result in complete system compromise, data exfiltration, and potential lateral movement within the network. When an attacker successfully creates a deployment project and executes code through the Bamboo agent, they gain the ability to perform actions such as accessing sensitive configuration files, modifying build scripts, or installing malicious software on the Bamboo server. The default local agent configuration exacerbates this risk, as it eliminates the need for network-based attack vectors and allows direct system-level access. This vulnerability aligns with ATT&CK technique T1059.001 for command and script injection, and T1078.004 for valid accounts, as it exploits legitimate user credentials to perform unauthorized system operations. The attack chain demonstrates how insufficient authorization controls can enable privilege escalation and remote code execution in continuous integration environments.
Organizations affected by this vulnerability should immediately apply the vendor-provided patches to versions 5.15.7 and 6.0.1, which properly implement the missing authorization checks for deployment project creation. System administrators should also review and tighten access controls for Bamboo user accounts, particularly those with minimal privileges. The remediation process should include disabling local agents if they are not strictly required for operations, or at minimum implementing strict network segmentation between the Bamboo server and other systems. Security monitoring should be enhanced to detect unusual deployment project creation patterns, and regular permission audits should be conducted to ensure that only authorized personnel have edit access to deployment configurations. This vulnerability highlights the importance of maintaining proper access control boundaries in development environments, as these systems often contain sensitive build artifacts and deployment configurations that can provide attackers with significant system access.