Secure Sockets Layer (SSL) is cryptographic protocol designed to provide communication security over the Internet. SSL Protocol 3.0 was released in 1996, and being widely used afterwards. Now SSL 3.0 is an obsolete and replaced by TLS 1.0 [RFC2246], TLS 1.1 [RFC4346], and TLS 1.2 [RFC5246], however, many TLS implementations remain backwards-compatible with SSL 3.0.

On October 14, 2014, Google researchers published a vulnerability in the design of SSL 3.0, which makes CBC mode of operation with SSL 3.0 vulnerable to the padding attack (CVE-2014-3566). The vulnerability was named as POODLE (Padding Oracle On Downgraded Legacy Encryption).

To eliminate the vulnerability completely, please disable the SSL 3.0 protocol in the client or in the server (or both).

Dell SonicWALL Threat Team has researched this vulnerability and released the following signatures to protect their customers:

• 5770 Downgraded TLS Traffic

The following existing application signature can also be used to detect SSL 3.0 traffic:

• 5153 SSL — SSLv3.0