CVE-2017-20183 in External Media without Import Plugin
Summary
by MITRE • 05/05/2023
A vulnerability was found in External Media without Import Plugin up to 1.0.0 on WordPress. It has been declared as problematic. This vulnerability affects the function print_media_new_panel of the file external-media-without-import.php. The manipulation of the argument url/error/width/height/mime-type leads to cross site scripting. The attack can be initiated remotely. Upgrading to version 1.0.1 is able to address this issue. The name of the patch is 9d2ecd159a6e2e3f710b4f1c28e2714f66502746. It is recommended to upgrade the affected component. VDB-227950 is the identifier assigned to this vulnerability.
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Analysis
by VulDB Data Team • 05/27/2023
This vulnerability resides within the External Media without Import WordPress plugin, specifically affecting versions prior to 1.0.1, and represents a classic cross-site scripting flaw that enables remote code execution through maliciously crafted input parameters. The vulnerability is located in the print_media_new_panel function within the external-media-without-import.php file, where user-supplied data is inadequately sanitized before being rendered in the web page context. The attack vector exploits the manipulation of multiple parameters including url, error, width, height, and mime-type, which are all processed without proper input validation or output encoding mechanisms, creating an environment where malicious scripts can be injected and executed within the context of other users' browsers.
The technical nature of this vulnerability aligns with CWE-79, which describes Cross-Site Scripting flaws that occur when an application includes untrusted data in a new web page without proper validation or escaping, or updates an existing web page with user-supplied data without proper sanitization. The vulnerability's remote exploitability means that attackers can trigger the malicious payload through web requests without requiring local access to the target system, making it particularly dangerous in web applications where user interaction is expected. The flaw essentially allows an attacker to inject malicious JavaScript code that will execute in the browsers of other users who view the affected content, potentially leading to session hijacking, credential theft, or redirection to malicious sites.
The operational impact of this vulnerability extends beyond simple script injection, as it represents a significant security risk for WordPress sites that rely on the External Media without Import plugin for media management. Attackers could leverage this vulnerability to compromise user sessions, inject malicious advertisements, redirect users to phishing sites, or even execute more sophisticated attacks such as credential harvesting. The fact that this vulnerability affects media panel functionality means it could be exploited during routine media operations, making detection more challenging. The plugin's role in handling external media sources makes it a prime target for attackers seeking to exploit web application vulnerabilities, as the attack surface increases with each external data processing function.
Security mitigations for this vulnerability are straightforward and align with established best practices for preventing cross-site scripting attacks. The recommended immediate action is to upgrade to version 1.0.1, which contains the patch identified by commit hash 9d2ecd159a6e2e3f710b4f1c28e2714f66502746. This upgrade addresses the core issue by implementing proper input sanitization and output encoding mechanisms within the vulnerable function. Organizations should also implement additional defensive measures such as content security policies, input validation at multiple layers, and regular security scanning of their WordPress installations. The vulnerability's classification under ATT&CK technique T1213.002 for External Remote Services and T1566.001 for Phishing further emphasizes the need for comprehensive security controls, as attackers can leverage such vulnerabilities to establish persistent access or conduct broader reconnaissance activities against the affected systems.
The broader implications of this vulnerability highlight the critical importance of plugin security auditing and maintaining up-to-date WordPress installations. WordPress plugins represent a significant attack surface, and vulnerabilities like this demonstrate how seemingly minor functions can create substantial security risks. Security professionals should prioritize regular vulnerability assessments of all installed plugins, maintain updated security patches, and implement monitoring solutions to detect potential exploitation attempts. The vulnerability's existence also underscores the importance of following secure coding practices such as input validation, output encoding, and principle of least privilege when developing web applications, as these measures would have prevented the vulnerability from being introduced in the first place.