CVE-2021-29503
19.05.2021, 20:15
HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a note can embed HTML tags in the Open Graph metadata section of the note, resulting in the frontend rendering the script tag as part of the `<head>` section. Unless your instance prevents guests from editing notes, this vulnerability allows unauthenticated attackers to inject JavaScript into notes that allow guest edits. If your instance prevents guests from editing notes, this vulnerability allows authenticated attackers to inject JavaScript into any note pages they have write-access to. This vulnerability is patched in version 1.8.2. As a workaround, one can disable guest edits until the next update.
| Vendor | Product | Version |
|---|---|---|
| hedgedoc | hedgedoc | 𝑥 < 1.8.2 |
𝑥
= Vulnerable software versions
Common Weakness Enumeration
- CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)The software receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
References