CVE-2014-8176: Buffer Overflow

The dtls1clearqueues function in ssl/d1lib.c in OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h frees data structures without considering that application data can arrive between a ChangeCipherSpec message and a Finished message, which allows remote DTLS peers to cause a denial of service (memory corruption and application crash) or possibly have unspecified other impact via unexpected application data.

— Launchpad

The following was reported by OpenSSL upstream:

This vulnerability does not affect current versions of OpenSSL. It existed in previous OpenSSL versions and was fixed in June 2014.

If a DTLS peer receives application data between the ChangeCipherSpec and Finished messages, buffering of such data may cause an invalid free, resulting in a segmentation fault or potentially, memory corruption.

This issue affected older OpenSSL versions 1.0.1, 1.0.0 and 0.9.8.

OpenSSL 0.9.8 DTLS users should upgrade to 0.9.8za OpenSSL 1.0.0 DTLS users should upgrade to 1.0.0m. OpenSSL 1.0.1 DTLS users should upgrade to 1.0.1h.

This issue was originally reported on March 28th 2014 in https://rt.openssl.org/Ticket/Display.html?id=3286 by Praveen Kariyanahalli, and subsequently by Ivan Fratric and Felix Groebert (Google). A fix was developed by zhu qun-ying.

Acknowledgements:

Red Hat would like to thank the OpenSSL project for reporting this issue.