The decode method in the OpenSSL::ASN1 module in Ruby before 2.2.8, 2.3.x before 2.3.5, and 2.4.x through 2.4.1 allows attackers to cause a denial of service (interpreter crash) via a crafted string.

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.