ISC DHCP Denial of Service Vulnerability

ISC DHCP is a set of open source Dynamic Host Configuration Protocol server software from ISC. ISC DHCP has a denial-of-service vulnerability that stems from the fact that when the function option_code_hash_lookup() is called from add_option(), it increases the option’s refcount field, but does not make a corresponding call to option_ dereference() is called accordingly to reduce the refcount field, the function add_option() is only used for the server’s response to lease query packets, and each lease query response calls this function for multiple options, which can be exploited by an attacker to trigger a reference counter overflow, resulting in a denial of service.