Related Vulnerabilities: CVE-2016-6309  

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. This issue was reported to OpenSSL on 23rd September 2016 by Robert Święcki (Google Security Team), and was found using honggfuzz.

Severity Critical

Remote Yes

Type Arbitrary code execution

Description

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.
This issue was reported to OpenSSL on 23rd September 2016 by Robert Święcki (Google Security Team), and was found using honggfuzz.

AVG-32 lib32-openssl 1:1.1.0a-1 Critical Not affected

AVG-31 openssl 1.1.0a-1 Critical Not affected

https://www.openssl.org/news/secadv/20160926.txt

This issue only affects OpenSSL 1.1.0a