Introduction: The CVE-2022-2311 vulnerability was discovered in the Find and Replace All WordPress plugin before the 1.3 version. The issue arises due to the lack of proper sanitization and escaping of certain parameters from the plugin's setting page, thereby causing a Reflected Cross-Site Scripting (XSS) issue. In this long read post, we will delve into the exploit details, provide a code snippet, and share links to the original references.

Exploit Details: Reflected Cross-Site Scripting (XSS) is a type of vulnerability that occurs when an attacker injects malicious scripts into a legitimate website or application, which then reflects the script back to the user. This can lead to stolen user data, session hijacking, or the spread of malware. In this case, an attacker takes advantage of the Find and Replace All plugin's setting page's unsanitized and unescaped parameters to inject a malicious script, effectively turning a legitimate page into a dangerous one.

One of the possible scenarios for exploiting this vulnerability is having a logged-in administrator visit a crafted URL containing a malicious payload. Once the administrator visits the URL, the injected code will execute in their browser, potentially stealing their session cookies, performing actions on their behalf, or modifying the content of the web page.

Code Snippet: The vulnerability can be demonstrated by visiting the following URL, which contains a JavaScript payload that triggers an alert prompt:

https://www.example.com/wp-admin/options-general.php?page=find_and_replace_all&tab=about_us&a=%22%3E%3Cscript%3Ealert%281%29%3C%2Fscript%3E

This URL points to the setting page of the Find and Replace All plugin on the WordPress administrative dashboard (replace "www.example.com" with the target website). The exploit payload is contained within the "a" parameter.

Notice the %22%3E%3Cscript%3Ealert%281%29%3C%2Fscript%3E part in the URL. This is a URL-encoded JavaScript payload, equivalent to "><script>alert(1)</script>.

When the vulnerable plugin processes this parameter, it does not sanitize or escape it, thus leading to a Reflected XSS issue. In this specific example, an alert prompt with the number "1" will be shown when an administrator visits the crafted URL. However, the exploit can be modified to carry out more harmful actions.

Original References

- CVE Details
- WP Vulnerability Database

Mitigation and Fix: To resolve this vulnerability, users should update the Find and Replace All WordPress plugin to version 1.3 or later as soon as possible. This update includes proper sanitization and escaping of parameters in the plugin's setting page, effectively preventing the Reflected XSS issue.

For users who are unable to update the plugin immediately, a possible temporary solution is to disable the Find and Replace All plugin until an update can be applied.

Conclusion: Reflected Cross-Site Scripting vulnerabilities can pose a significant risk to both website administrators and end-users. As demonstrated in this post, the Find and Replace All WordPress plugin versions before 1.3 are susceptible to such exploits due to unsanitized and unescaped parameters. Users should update their plugin to version 1.3 or later to ensure protection from potential attacks. Additionally, developers should always consider proper input/output sanitization and escaping to prevent such vulnerabilities in their code.

Timeline

Published on: 11/28/2022 14:15:00 UTC
Last modified on: 11/30/2022 03:40:00 UTC