CVE-2021-42548 in Share-one-Drive Plugin
Summary
by MITRE • 12/13/2021
Insufficient Input Validation in the search functionality of Wordpress plugin Share-one-Drive prior to 1.15.3 allows unauthenticated user to craft a reflected Cross-Site Scripting attack.
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Analysis
by VulDB Data Team • 12/16/2021
The vulnerability CVE-2021-42548 represents a critical security flaw in the Share-one-Drive WordPress plugin affecting versions prior to 1153. This issue stems from inadequate input validation within the plugin's search functionality, creating an avenue for reflected cross-site scripting attacks that can be exploited by unauthenticated attackers. The vulnerability manifests when user-supplied input is not properly sanitized or validated before being processed and returned in HTTP responses, thereby enabling malicious actors to inject arbitrary script code into web pages viewed by other users. The affected plugin operates as a file sharing solution that allows users to upload and share files within WordPress environments, making the search functionality a prime target for exploitation due to its frequent interaction with user input.
The technical implementation of this vulnerability aligns with CWE-79 which describes improper neutralization of input during web page generation, specifically in the context of reflected cross-site scripting. When a user submits a search query through the plugin's interface, the input parameters are directly incorporated into the response without adequate sanitization measures. This creates a reflected XSS vector where malicious payloads can be embedded in search parameters and executed in the context of other users' browsers. The vulnerability is particularly concerning because it requires no authentication, meaning any visitor to a website running the vulnerable plugin can potentially exploit this weakness to execute malicious scripts in the browsers of other site visitors. The reflected nature of the attack means that the malicious script code is reflected back from the server to the user's browser, typically through URL parameters or form fields.
The operational impact of this vulnerability extends beyond simple script execution, as it can be leveraged for various malicious activities including session hijacking, credential theft, defacement of web content, and redirection to malicious sites. Attackers can craft specially formatted search queries that, when processed by the vulnerable plugin, will inject malicious JavaScript code into the page response. This code can then execute in the context of other users' browsers, potentially allowing attackers to steal cookies, session tokens, or other sensitive information. The attack surface is particularly wide given that WordPress plugins are frequently used across various websites, and the vulnerability affects a plugin that provides file sharing capabilities, making it attractive to attackers seeking to compromise user sessions or gain unauthorized access to shared resources. The reflected nature of the vulnerability also means that successful exploitation can occur through social engineering campaigns where attackers trick users into clicking malicious links containing the crafted payloads.
Mitigation strategies for CVE-2021-42548 should prioritize immediate patching of the Share-one-Drive plugin to version 1153 or later, which includes proper input validation and sanitization measures. Organizations should also implement comprehensive input validation at multiple layers including application-level filtering, web application firewalls, and output encoding to prevent script injection attempts. The implementation of Content Security Policy headers can provide additional protection by restricting the sources from which scripts can be executed, thereby limiting the impact of successful XSS attempts. Regular security audits and vulnerability assessments should be conducted to identify similar input validation weaknesses in other WordPress plugins and themes, as reflected XSS vulnerabilities are common across web applications and often stem from similar architectural flaws. Network monitoring and intrusion detection systems should be configured to detect suspicious search parameter patterns that may indicate attempted exploitation of this vulnerability. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates across all WordPress installations and plugins, particularly for widely used plugins that may be targeted by automated exploitation tools. The vulnerability demonstrates the critical importance of proper input validation and output encoding practices in web application security, aligning with ATT&CK technique T1203 which covers exploitation for credential access through web application vulnerabilities.