This security update addresses issues that were caused by patches
included in our previous security update, released on 22nd September
2016. Given the Critical severity of one of these flaws we have
chosen to release this advisory immediately to prevent upgrades to the
affected version, rather than delaying in order to provide our usual
Fix Use After Free for large message sizes (CVE-2016-6309)
This issue only affects OpenSSL 1.1.0a, released on 22nd September 2016.
The patch applied to address CVE-2016-6307 resulted in an issue where if a
message larger than approx 16k is received then the underlying buffer to store
the incoming message is reallocated and moved. Unfortunately a dangling pointer
to the old location is left which results in an attempt to write to the
previously freed location. This is likely to result in a crash, however it
could potentially lead to execution of arbitrary code.
OpenSSL 1.1.0 users should upgrade to 1.1.0b
This issue was reported to OpenSSL on 23rd September 2016 by Robert
ÅwiÄcki (Google Security Team), and was found using honggfuzz. The fix
was developed by Matt Caswell of the OpenSSL development team.
This issue only affects OpenSSL 1.0.2i, released on 22nd September 2016.
A bug fix which included a CRL sanity check was added to OpenSSL 1.1.0
but was omitted from OpenSSL 1.0.2i. As a result any attempt to use
CRLs in OpenSSL 1.0.2i will crash with a null pointer exception.
OpenSSL 1.0.2i users should upgrade to 1.0.2j
The issue was reported to OpenSSL on 22nd September 2016 by Bruce Stephens and
Thomas Jakobi. The fix was developed by Matt Caswell of the OpenSSL development