CVE-2016-6517 in Liferay
Summary
by MITRE
Directory traversal vulnerability in Liferay 5.1.0 allows remote attackers to have unspecified impact via a %2E%2E (encoded dot dot) in the minifierBundleDir parameter to barebone.jsp.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2016-6517 represents a critical directory traversal flaw within Liferay Portal version 5.1.0 that exposes the platform to remote exploitation by malicious actors. This vulnerability specifically affects the barebone.jsp component which processes the minifierBundleDir parameter through an insecure input validation mechanism. The weakness stems from the application's failure to properly sanitize user-supplied input containing encoded directory traversal sequences, allowing attackers to manipulate file system access paths through the %2E%2E URL encoding pattern that represents the traditional dot-dot traversal sequence.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious request containing the encoded dot-dot sequence within the minifierBundleDir parameter, enabling them to traverse directories beyond the intended application boundaries. This flaw falls under the CWE-22 category of Improper Limitation of a Pathname to a Restricted Directory, commonly known as Directory Traversal or Path Traversal. The vulnerability demonstrates how insufficient input validation and sanitization can lead to arbitrary file access, potentially allowing attackers to read sensitive files, execute arbitrary code, or even compromise the entire underlying system. The impact of such a vulnerability extends beyond simple information disclosure as it can enable attackers to escalate privileges and gain deeper access to the application infrastructure.
From an operational perspective, this vulnerability poses significant risks to organizations utilizing Liferay 5.1.0 as it provides remote attackers with a straightforward method to bypass access controls and potentially access restricted system resources. The attack vector is particularly dangerous because it requires no authentication and can be executed through standard web browser interactions, making it highly exploitable in real-world scenarios. The unspecified impact mentioned in the CVE description suggests that the vulnerability could potentially lead to complete system compromise, data exfiltration, or service disruption depending on the specific implementation and system configuration. Security teams should consider this vulnerability as a high-priority threat that could be leveraged in combination with other attack techniques to establish persistent access to target environments.
The remediation strategy for CVE-2016-6517 requires immediate implementation of input validation and sanitization measures within the Liferay application, specifically targeting the minifierBundleDir parameter processing within barebone.jsp. Organizations should implement proper path validation that rejects or normalizes any input containing directory traversal sequences, including both encoded and decoded forms of the traversal patterns. The solution should align with established security best practices and standards such as those outlined in the OWASP Top Ten and the NIST Cybersecurity Framework. Additionally, implementing proper access controls, input filtering mechanisms, and regular security audits can help prevent similar vulnerabilities from occurring in the future. System administrators should also consider applying the official patches released by Liferay to address this specific vulnerability and ensure that all components are updated to the latest secure versions to prevent exploitation attempts.