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

2017-04-18T07:35:36
ID H1:221787
Type hackerone
Reporter theyarestone
Modified 2017-05-25T01:33:01

Description

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.

refer: https://www.openssl.org/news/secadv/20160922.txt