CVE-2019-12831

Severity CVSS v4.0:

Pending analysis

Type:

CWE-20 Input Validation

Publication date:

15/06/2019

Last modified:

17/06/2019

Description

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.

Impact

Vector 3.x

CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.20 HIGH
Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.20

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:L/Au:S/C:P/I:P/A:P CVSS v2.0 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: AV:N/AC:L/Au:S/C:P/I:P/A:P

Attack Vector (AV): Network
Attack Complexity (AC): Low
Authentication (Au): Single
Confidentiality (C): Physical
Integrity (I): Physical
Availability (A): Physical