GHSA-ggqx-43h2-55jp

Yeswiki Vulnerable to Unauthenticated Reflected Cross-site Scripting

### Summary **Vulnerable Version:** Yeswiki < v4.5.4 **Category:** Injection **CWE: 79:** Improper Neutralization of Input During Web Page Generation (CWE-79) **CVSS:** 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N) **Vulnerable Endpoint:** `/?BazaR` **Vulnerable Parameter:** `idformulaire` **Payload:** `<script>alert(1)</script>` ### Details Reflected Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into otherwise benign and trusted websites. XSS attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser-side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user within the output it generates without validating or encoding it. ### PoC 1. Visit the endpoint as mentioned below and see that an alert box pops up: **URL with Payload:** `https://yeswiki.net/?BazaR&vue=formulaire&action=confirm_delete&idformulaire=%3cscript%3ealert(1)%3c%2fscript%3e` ### Impact An attacker can use a reflected cross-site scripting attack to steal cookies from an authenticated user by having them click on a malicious link. Stolen cookies allow the attacker to take over the user’s session. This vulnerability may also allow attackers to deface the website or embed malicious content.