The Piwik 1.5 release addresses a critical security vulnerability, which affect all Piwik users that have let granted some access to the “anonymous” user. Users should upgrade immediately.


Piwik 1.5 contains a remotely exploitable vulnerabiliy that could allow a remote attacker to execute arbitrary code. Only Installations that have granted untrusted view access to their stats (ie. grant “view” access to a website to anonymous) are at risk.

CVE: CVE-2011-4941
More information:
Known Versions Affected: Piwik 1.2, 1.3, and 1.4


This issue was disclosed to us privately and safely. Our thanks to Neal Poole for discovering and reporting the issue to the Piwik Security Team. Neal is the first bounty recipient of Piwik’s Security Bug Bounty program.

This release also includes Zend Framework 1.11.6 which addresses a potential SQL injection vector when using PDO_MySql. Piwik users should be unaffected as it has used UTF-8 since Piwik 0.5.

Anthon Pang

- active contributor for years, Anthon has designed some some major features in Piwik such as the first version of the Javascript tracker. He still regularly advises the team.