OpenSSL (IBB): Malformed SHA512 ticket DoS (CVE-2016-6302)

ID H1:221787
Type hackerone
Reporter theyarestone
Modified 2017-05-25T01:33:01


If a server uses SHA512 for TLS session ticket HMAC it is vulnerable to a DoS attack where a malformed ticket will result in an OOB read which will ultimately crash.

The use of SHA512 in TLS session tickets is comparatively rare as it requires a custom server callback and ticket lookup mechanism.