CVE-2019-12831

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.

CVSS v3.0 7.2 HIGH
CVSS v2.0 6.5 MEDIUM

7.2^/10

CVSS v3.0 : HIGH

Vector : AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Exploitability : 1.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

6.5^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:S/C:P/I:P/A:P

Exploitability : 8.0 / Impact : 6.4

Access Vector NETWORK

Access Complexity LOW

Authentication SINGLE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://blog.ripstech.com/2019/mybb-stored-xss-to-rce/	Exploit Vendor Advisory
https://blog.mybb.com/2019/06/10/mybb-1-8-21-released-security-maintenance-release/	Release Notes Vendor Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*

Information

Published : 2019-06-15 11:29

Updated : 2019-06-17 12:01

NVD link : CVE-2019-12831

Mitre link : CVE-2019-12831

JSON object : View

CWE

CWE-20

Improper Input Validation

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Products Affected

mybb

mybb

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