NULL pointer dereference in OpenSSL - CVE-2016-7053

Detailed vulnerability description

The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference error when parsing ASN.1 CHOICE type within CMS structures in OpenSSL. A remote attacker can send a specially crafted request to vulnerable service and initiate the NULL value being passed to the structure callback if an attempt is made to free certain invalid encodings.

Successful exploitation may result in denial of service (DoS) attack.

How to mitigate CVE-2016-7053

OpenSSL 1.1.0 users should upgrade to 1.1.0c

This issue does not affect OpenSSL versions prior to 1.1.0

Sources

• https://www.openssl.org/news/secadv/20161110.txt