MyBB up to 1.8.23 MyCode Visual Editor POST Parameter DOM-Based cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in MyBB up to 1.8.23. Affected by this vulnerability is an unknown functionality of the component MyCode Visual Editor. The manipulation as part of POST Parameter results in cross site scripting (DOM-Based). This vulnerability is identified as CVE-2020-15139. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in MyBB up to 1.8.23 (Content Management System). Affected is an unknown part of the component MyCode Visual Editor. The manipulation as part of a POST Parameter leads to a cross site scripting vulnerability (DOM-Based). CWE is classifying the issue as CWE-79. The product 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. This is going to have an impact on integrity. CVE summarizes:

In MyBB before version 1.8.24, the custom MyCode (BBCode) for the visual editor doesn't escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. The weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. After upgrading MyBB to 1.8.24, make sure to update the version attribute in the `codebuttons` template for non-default themes to serve the latest version of the patched `jscripts/bbcodes_sceditor.js` file.

The weakness was released 08/10/2020 (GitHub Repository). The advisory is shared for download at github.com. This vulnerability is traded as CVE-2020-15139 since 06/25/2020. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 1.8.24 eliminates this vulnerability.

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Productinfo

Type

• Content Management System

Name

• MyBB

Version

• 1.8.0
• 1.8.1
• 1.8.2
• 1.8.3
• 1.8.4
• 1.8.5
• 1.8.6
• 1.8.7
• 1.8.8
• 1.8.9
• 1.8.10
• 1.8.11
• 1.8.12
• 1.8.13
• 1.8.14
• 1.8.15
• 1.8.16
• 1.8.17
• 1.8.18
• 1.8.19
• 1.8.20
• 1.8.21
• 1.8.22
• 1.8.23

License

• open-source

Website

• Product: https://mybb.com/

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