CVE-2011-10018

critical

Description

myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code. The backdoor allowed remote attackers to execute arbitrary PHP code by injecting payloads into a specially crafted collapsed cookie. This vulnerability was introduced during packaging and was not part of the intended application logic. Exploitation requires no authentication and results in full compromise of the web server under the context of the web application.

References

Advisories
More

https://www.vulncheck.com/advisories/mybb-backdoor-arbitrary-command-execution

https://web.archive.org/web/20111015224948/http://secunia.com/advisories/46300/

https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/unix/webapp/mybb_backdoor.rb

https://blog.mybb.com/2011/10/06/1-6-4-security-vulnerabilit/

Details

Source: Mitre, NVD

Published: 2025-08-13

Updated: 2025-08-14

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 10

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Severity: Critical

EPSS

EPSS: 0.00262