CVE-2015-4704 in Zip Attachments Plugin
Summary
by MITRE
Directory traversal vulnerability in the Download Zip Attachments plugin 1.0 for WordPress allows remote attackers to read arbitrary files via a .. (dot dot) in the File parameter to download.php.
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Analysis
by VulDB Data Team • 12/07/2022
The CVE-2015-4704 vulnerability represents a critical directory traversal flaw within the Download Zip Attachments plugin version 1.0 for WordPress platforms. This vulnerability stems from insufficient input validation in the file parameter processing within the download.php script, creating an exploitable condition that allows remote attackers to access arbitrary files on the target system. The flaw specifically manifests when the plugin fails to properly sanitize user-supplied input containing directory traversal sequences such as .. or %2e%2e, which are commonly used to navigate up directory levels in file systems. The vulnerability affects WordPress installations where this specific plugin is active and configured to handle file downloads, making it particularly dangerous in environments where multiple plugins are deployed without proper security auditing.
From a technical perspective, the vulnerability operates by manipulating the File parameter in the download.php endpoint to include directory traversal sequences that bypass normal file access controls. When the plugin processes these malicious inputs without proper sanitization, it allows attackers to specify file paths that extend beyond the intended download directories, potentially accessing sensitive system files including configuration files, database credentials, user information, and other privileged resources. The flaw aligns with CWE-22, which classifies directory traversal vulnerabilities as weaknesses that occur when applications fail to properly validate file paths, allowing attackers to access files outside of the intended directory structure. This type of vulnerability is particularly concerning because it can enable attackers to extract critical system information, potentially leading to complete system compromise.
The operational impact of CVE-2015-4704 extends beyond simple file access, as it provides attackers with the capability to escalate privileges and potentially gain deeper system access. Attackers can leverage this vulnerability to read WordPress configuration files, database credentials, and other sensitive information that could be used for further exploitation. The vulnerability also enables attackers to potentially upload malicious files or modify existing system files, creating persistent backdoors or facilitating lateral movement within the network. From an attacker's perspective, this vulnerability fits within the ATT&CK framework under the technique T1083 (File and Directory Discovery) and T1078 (Valid Accounts) as it allows for reconnaissance and privilege escalation activities. The impact is particularly severe in multi-tenant hosting environments or shared hosting scenarios where multiple WordPress installations exist on the same server, as the vulnerability could potentially affect other sites hosted on the same infrastructure.
Mitigation strategies for CVE-2015-4704 should include immediate plugin updates to versions that address the directory traversal vulnerability, which typically involves implementing proper input sanitization and validation mechanisms. Organizations should also implement web application firewalls that can detect and block malicious directory traversal attempts, particularly those involving sequences like .. or %2e%2e in file parameters. Additionally, proper file access controls should be enforced through filesystem permissions and the principle of least privilege, ensuring that web applications can only access files within designated directories. Security monitoring should include detection of unusual file access patterns and attempts to access system directories. The vulnerability highlights the importance of regular security audits and patch management processes, as it demonstrates how outdated or poorly maintained plugins can create significant security risks. Organizations should also consider implementing automated scanning tools that can identify vulnerable plugins and configurations, as well as establishing security awareness programs for developers who create or maintain WordPress plugins to prevent similar issues in future development cycles.