CVE-2018-8889 in Enterprise Mobility Server
Summary
by MITRE
A directory traversal vulnerability in the Connect Service of the BlackBerry Enterprise Mobility Server (BEMS) 2.8.17.29 and earlier could allow an attacker to retrieve arbitrary files in the context of a BEMS administrator account.
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Analysis
by VulDB Data Team • 03/25/2020
The directory traversal vulnerability identified as CVE-2018-8889 affects the BlackBerry Enterprise Mobility Server version 2.8.17.29 and earlier implementations. This security flaw resides within the Connect Service component of the BEMS platform, which serves as a critical communication bridge between enterprise mobile devices and corporate email systems. The vulnerability represents a significant risk to organizations relying on BlackBerry's enterprise mobility solutions for their mobile device management and email security infrastructure.
The technical flaw manifests through improper input validation within the Connect Service's file handling mechanisms. Attackers can exploit this weakness by crafting malicious requests that manipulate file path references to navigate beyond the intended directory boundaries. When the service processes these crafted requests, it fails to properly sanitize user-supplied input, allowing attackers to traverse the file system hierarchy and access files that should remain restricted. This vulnerability specifically impacts the administrative context of the BEMS system, meaning that successful exploitation requires an attacker to first obtain valid administrative credentials, though the privilege escalation aspect remains minimal as the attack targets existing administrative access.
The operational impact of CVE-2018-8889 extends beyond simple unauthorized file access, as it enables potential data exfiltration from sensitive enterprise systems. An attacker with administrative access could retrieve configuration files, user credentials, email contents, and other sensitive data stored within the BEMS environment. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous in enterprise environments where BlackBerry BEMS serves as a central hub for mobile device management. Organizations using this platform face risks of intellectual property theft, regulatory compliance violations, and potential compromise of their entire mobile device ecosystem.
Organizations should prioritize immediate patching of affected BlackBerry Enterprise Mobility Server installations to remediate this vulnerability. The official BlackBerry security advisory recommends upgrading to version 2.8.17.30 or later, which contains the necessary fixes for the directory traversal issue. Additionally, network segmentation and access controls should be implemented to limit administrative access to the BEMS system, reducing the attack surface for potential exploitation. Security monitoring should be enhanced to detect unusual file access patterns and directory traversal attempts within the BEMS environment. This vulnerability aligns with CWE-22, which specifically addresses directory traversal and path traversal flaws in software systems. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1083, which covers discovering file and directory permissions, and T1566, related to spearphishing with malicious attachments that could leverage such vulnerabilities for initial access.
The broader implications of this vulnerability highlight the critical importance of proper input validation and secure coding practices in enterprise mobility management systems. Organizations should conduct comprehensive security assessments of their mobile device management infrastructure to identify similar vulnerabilities in other components. Regular security updates and vulnerability management processes become essential for maintaining the security posture of enterprise mobility solutions. The incident underscores the need for continuous monitoring of security advisories from mobile device management vendors and proactive implementation of security patches to protect against known vulnerabilities in critical infrastructure components.