CVE-2017-0898: Buffer Overflow

Ruby before 2.4.2, 2.3.5, and 2.2.8 is vulnerable to a malicious format string which contains a precious specifier () with a huge minus value. Such situation can lead to a buffer overrun, resulting in a heap memory corruption or an information disclosure from the heap.

— Launchpad

Ruby. Multiple issues in Ruby were addressed in this update.

There is a buffer underrun vulnerability in the sprintf method of Kernel module. If a malicious format string which contains a precious specifier () is passed and a huge minus value is also passed to the specifier, buffer underrun may be caused. In such situation, the result may contains heap, or the Ruby interpreter may crash.

External References:

https://www.ruby-lang.org/en/news/2017/09/14/sprintf-buffer-underrun-cve-2017-0898/

— Red Hat