CVE-2016-6304: High severity Advantech Spectre RT ERT351 firmware Versions 5.1.3 and prior vulnerability

Multiple memory leaks in t1lib.c in OpenSSL before 1.0.1u, 1.0.2 before 1.0.2i, and 1.1.0 before 1.1.0a allow remote attackers to cause a denial of service (memory consumption) via large OCSP Status Request extensions.

Quoting form the draft of the OpenSSL upstream advisory:

OCSP Status Request extension unbounded memory growth (CVE-2016-6304) =====================================================================

Severity: High

A malicious client can send an excessively large OCSP Status Request extension. If that client continually requests renegotiation, sending a large OCSP Status Request extension each time, then there will be unbounded memory growth on the server. This will eventually lead to a Denial Of Service attack through memory exhaustion. Servers with a default configuration are vulnerable even if they do not support OCSP. Builds using the "no-ocsp" build time option are not affected.

OpenSSL 1.1.0 users should upgrade to 1.1.0a OpenSSL 1.0.2 users should upgrade to 1.0.2i OpenSSL 1.0.1 users should upgrade to 1.0.1u

This issue was reported to OpenSSL on 29th August 2016 by Shi Lei (Gear Team, Qihoo 360 Inc.). The fix was developed by Matt Caswell of the OpenSSL development team.

— Red Hat