In consequence of an insufficient threat model, ownCloud is storing all user's private RSA keys in clear text in PHP session files. These unencrypted private keys can be accessed by every web application that has the privilege of the web server user. The affected files exposing cryptographic keys will be stored in the PHP session directory for a number of hours until they are removed. All versions of ownCloud since the introduction of the encryption module in version 5.0.7 including version 7.0.0 are affected.
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