ownCloud Desktop Client before 1.8.2 does not call QNetworkReply::ignoreSslErrors with the list of errors to be ignored, which allows man-in-the-middle attackers to bypass the user's certificate distrust decision and obtain sensitive information by leveraging a self-signed certificate and a connection to a server using its own self-signed certificate.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-4456
• owncloud/client#3283
• https://owncloud.org/security/advisory/?id=oc-sa-2015-009
• http://www.debian.org/security/2015/dsa-3363
• http://www.securityfocus.com/bid/75354