CVE-2021-24657 Scanner

The Limit Login Attempts plugin for WordPress is widely used by website administrators to protect their sites against too many failed login attempts, which could be indicative of brute force attacks. Available through WordPress.org, it facilitates setting a cap on the number of login attempts from a specific IP address, locking them out after multiple failures. This plugin is typically used by WordPress users who wish to enhance their site's security without deeply altering existing infrastructure. Many users prefer this plugin because it is easy to install and configure, featuring intuitive options that non-technical users can comfortably manage. Its core functionality is integral for website owners aiming to add an extra layer of security to the default WordPress installation. Given its focus on login attempts, the plugin also provides useful logs and reports to the administrators for better monitoring of their sites' defense status.

The vulnerability in question is a stored cross-site scripting (XSS) issue. It arises because the plugin fails to properly escape IP addresses from request headers such as X-Forwarded-For before displaying them in the admin panel's reports. Stored XSS vulnerabilities allow malicious scripts to be permanently stored on a target server, in this case within WordPress reports, which can be triggered later when an admin views these reports. This specific vulnerability can be particularly risky as an attacker could exploit it to execute arbitrary scripts in the context of an administrative session. The impact is significant since it can lead to severe consequences such as session hijacking or site defacement if exploited effectively. Understanding the potential for stored XSS to seamlessly integrate into routine server operations poses a substantial security threat, highlighting the need for diligent escape mechanisms for any user-inputted data.

The technical details of this vulnerability rest on manipulating certain HTTP request headers. Unauthenticated attackers can inject malicious scripts using headers like X-Forwarded-For to deliver crafted payloads that will run in the admin dashboard whenever the logs are viewed. This is due to the lack of sanitization or escaping of these header values before they are output in the reports section of the admin panel. By failing to apply stringent sanitation routines, malicious actors can embed JavaScript payloads even though they do not have authenticated access. The delicate nature of this exploit makes it particularly dangerous because it affects administrative interaction directly. Attacks can be carried out silently, without the immediate awareness of the website administrator, allowing the script to capture sensitive administrative data.

When this vulnerability is exploited, attackers can execute arbitrary scripts within the context of the authenticated administrator's browser session. The consequences can range from simple defacements to complicated session hijackings. This means attackers might control or manipulate admin functions, leading to unauthorized actions being performed on the site, such as changing settings, installing malicious plugins, or even accessing other sensitive data. The breach in security also opens the door for potential phishing attacks against the site administrators. The ripple effect of such an exploitation extends to potential loss of trust from the website's user base if the attack leads to visible alterations or the compromise of other protected data.

REFERENCES

• https://wordpress.org/plugins/miniorange-limit-login-attempts
• https://nvd.nist.gov/vuln/detail/CVE-2021-24657