MyBB up to 1.8.18 Visual Editor Persistent cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in MyBB up to 1.8.18. The impacted element is an unknown function of the component Visual Editor. Executing a manipulation can lead to cross site scripting (Persistent). This vulnerability is registered as CVE-2018-17128. It is possible to launch the attack remotely. Furthermore, an exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in MyBB up to 1.8.18 (Content Management System). This vulnerability affects an unknown part of the component Visual Editor. The manipulation with an unknown input leads to a cross site scripting vulnerability (Persistent). The CWE definition for the vulnerability is 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. As an impact it is known to affect integrity. CVE summarizes:

A Persistent XSS issue was discovered in the Visual Editor in MyBB before 1.8.19 via a Video MyCode.

The bug was discovered 09/11/2018. The weakness was published 09/17/2018 (Website). The advisory is shared for download at blog.mybb.com. This vulnerability was named CVE-2018-17128 since 09/16/2018. The attack can be initiated remotely. A single authentication is necessary for exploitation. Successful exploitation requires user interaction by the victim. Technical details are unknown but a public exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 6 days. During that time the estimated underground price was around $0-$5k.

Upgrading to version 1.8.19 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Exploit-DB (45449). VulDB is the best source for vulnerability data and more expert information about this specific topic.

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

License

• open-source

Website

• Product: https://mybb.com/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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