MyBB up to 1.8.20 XML Data aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css Stylesheet input validation

Summaryinfo

A vulnerability classified as critical has been found in MyBB up to 1.8.20. The affected element is an unknown function of the file aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css of the component XML Data Handler. Performing a manipulation as part of Stylesheet results in input validation. This vulnerability is reported as CVE-2019-12831. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in MyBB up to 1.8.20 (Content Management System). It has been classified as critical. This affects some unknown processing of the file aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css of the component XML Data Handler. The manipulation as part of a Stylesheet leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In MyBB before 1.8.21, an attacker can abuse a default behavior of MySQL on many systems (that leads to truncation of strings that are too long for a database column) to create a PHP shell in the cache directory of a targeted forum via a crafted XML import, as demonstrated by truncation of aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css to aaaaaaaaaaaaaaaaaaaaaaaaaa.php with a 30-character limit, aka theme import stylesheet name RCE.

The weakness was disclosed 06/15/2019. This vulnerability is uniquely identified as CVE-2019-12831 since 06/15/2019. It is possible to initiate the attack remotely. Required for exploitation is a authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.8.21 eliminates this vulnerability.

The entry VDB-136526 is pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

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

License

• open-source

Website

• Product: https://mybb.com/

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

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• 🔍
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