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

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HIGH

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

Published Jun 15, 2019

7.2

HIGH

CVSS 3.0

EPSS 1.47%

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.

Affected products

Remediation

No remediation recorded yet.

Weaknesses (1)

CWE-20

Improper Input Validation

References (3)

https://blog.mybb.com/2019/06/10/mybb-1-8-21-released-security-maintenance-release/
x_refsource_MISCRelease NotesVendor Advisory
https://blog.ripstech.com/2019/mybb-stored-xss-to-rce/
x_refsource_MISCExploitVendor Advisory
https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4411
Advisory

Link	Providers	Tags
https://blog.mybb.com/2019/06/10/mybb-1-8-21-released-security-maintenance-release/		x_refsource_MISCRelease NotesVendor Advisory
https://blog.ripstech.com/2019/mybb-stored-xss-to-rce/		x_refsource_MISCExploitVendor Advisory
https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4411		Advisory

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED

Assigner mitre

Published Jun 15, 2019

Updated Aug 4, 2024

Reserved Jun 15, 2019

Link CVE-2019-12831

CISA Vulnrichment

No data

NVD

Status Modified

Modified Jun 17, 2026

Link CVE-2019-12831

Red Hat

No data

ENISA EUVD

Assigner mitre

Published Jun 15, 2019

Updated Aug 4, 2024

Link EUVD-2019-4411

GitHub

No data