WordPress FlagEm Cross-Site Scripting Scanner

The WordPress FlagEm plugin is a widely-used tool that extends the functionality of WordPress websites by allowing site administrators to manage user-generated content. It is primarily utilized by bloggers, website owners, and administrators to ensure user engagement while maintaining control over content. Designed for ease of use, the plugin enables non-technical users to flag and categorize content based on specific parameters. This increased control allows for a streamlined moderation process and enhanced site security. As with many plugins, FlagEm offers various integrations that allow it to function seamlessly with other WordPress extensions. Given its wide deployment, potential vulnerabilities within the plugin can significantly impact the numerous sites that rely on it.

Cross-Site Scripting (XSS) is a type of vulnerability that occurs when a web application includes user input in its output without proper validation or encoding. This vulnerability can allow an attacker to inject malicious scripts into web pages viewed by other users. Typically, the injected code is interpreted as legitimate content by the browser, potentially leading to cookie theft or other malicious activities. An XSS vulnerability can compromise user data and enable attackers to impersonate legitimate users in the security context of the target site. Many plugins, such as WordPress FlagEm, can become vectors for XSS attacks if not properly secured. Detecting and mitigating these vulnerabilities is crucial to protect user data and maintain site integrity.

In the case of the WordPress FlagEm plugin, the vulnerability lies in the 'flagit.php' script where user input is improperly handled. The 'cID' parameter is particularly susceptible, allowing attackers to inject JavaScript code, which is then executed in the user's browser. The improper filtering of this parameter results in scripts being embedded in a site's HTML, enabling the execution of the 'document.domain' alert. Such technical details highlight the critical nature of ensuring robust input validation and encoding practices. Additionally, the presence of certain response headers further confirms the execution context of this vulnerability.

If exploited, an XSS vulnerability in the WordPress FlagEm plugin can have several detrimental effects. Attackers could execute arbitrary code within a user's browser, leading to unauthorized actions carried out without the user's knowledge. This could include session hijacking, allowing attackers to impersonate users and access sensitive information. Furthermore, injected scripts might also redirect users to phishing sites or download malicious software. The overall impact could include compromised site integrity, loss of user trust, and potentially severe legal and financial consequences for site owners.

REFERENCES

• https://www.exploit-db.com/exploits/38674
• https://vulners.com/packetstorm/PACKETSTORM:122505