Improper Input Validation

Summary

RIOT is an operating system for internet of things (IoT) devices. In version 2024.04 and prior, the function `_parse_advertise`, located in `/sys/net/application_layer/dhcpv6/client.c`, has no minimum header length check for `dhcpv6_opt_t` after processing `dhcpv6_msg_t`. This omission could lead to an out-of-bound read, causing system inconsistency. Additionally, the same lack of a header length check is present in the function `_preparse_advertise`, which is called by `_parse_advertise` before handling the request. As of time of publication, no known patched version exists.