CVE-2015-5953 in ownCloud Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the activity application in ownCloud Server before 7.0.5 and 8.0.x before 8.0.4 allows remote authenticated users to inject arbitrary web script or HTML via a " (double quote) character in a filename in a shared folder.
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Analysis
by VulDB Data Team • 04/01/2025
The CVE-2015-5953 vulnerability represents a critical cross-site scripting flaw within the activity application of ownCloud Server versions prior to 7.0.5 and 8.0.x before 8.0.4. This vulnerability specifically targets the handling of filename characters within shared folder contexts, creating a pathway for authenticated attackers to execute malicious web scripts or HTML code in the browsers of other users. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly escape special characters, particularly the double quote character, when processing filenames in shared folder environments.
The technical exploitation of this vulnerability occurs through the manipulation of filename parameters within shared folder structures. When an authenticated user uploads or modifies a file containing a double quote character in its name, the application fails to adequately sanitize this input before rendering it in the user interface. This creates a persistent XSS vector where the malicious payload can be executed in the context of other users' browsers who access the shared folder containing the compromised filename. The vulnerability is particularly dangerous because it leverages the trust relationship inherent in shared folder functionality, where users expect to safely access files from colleagues or collaborators.
From an operational impact perspective, this vulnerability enables attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and unauthorized access to sensitive information within the ownCloud environment. The attack requires only authenticated access to the system, making it particularly concerning as it can be exploited by insiders or compromised accounts. The XSS payload can be crafted to steal session cookies, redirect users to malicious sites, or inject additional malicious code that persists across user sessions. This vulnerability directly violates the principle of least privilege and can lead to complete compromise of user accounts and potentially the entire ownCloud instance.
Security professionals should note that this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in software applications. The ATT&CK framework categorizes this vulnerability under T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1566.001 for "Phishing: Spearphishing Attachment" when considering the potential for attackers to leverage this vulnerability to deliver malicious payloads. Organizations should implement immediate mitigations including upgrading to patched versions of ownCloud Server, implementing proper input validation and output encoding for all user-supplied data, and deploying web application firewalls to detect and block malicious payloads. Additionally, security awareness training for users regarding the risks of accessing shared folders from untrusted sources and regular security audits of shared folder configurations can significantly reduce the attack surface and potential impact of such vulnerabilities.