CVSS 4.0
10.0 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCVE-2011-10018
Critical (10.0) in mybb mybb. EPSS 2.9% chance of exploitation in the next 30 days.
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.
Severity
CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- EPSS
- 2.9% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-94, CWE-912
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mybb:mybb
References
- https://blog.mybb.com/2011/10/06/1-6-4-security-vulnerabilit/
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/unix/webapp/mybb_backdoor.rb
- https://web.archive.org/web/20111015224948/http://secunia.com/advisories/46300/
- https://www.exploit-db.com/exploits/17949
- https://www.vulncheck.com/advisories/mybb-backdoor-arbitrary-command-execution