miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.

miniupnp before 4c90b87, as used in Bitcoin Core before 0.12 and other products, lacks checks for snprintf return values, leading to a buffer overflow and significant data leak, a different vulnerability than CVE-2019-12107. In Bitcoin Core before 0.12, remote code execution was possible in conjunction with CVE-2015-6031 exploitation.