session_by_pid(pid_t pid)
{
	int i;
	debug("session_by_pid: pid %ld", (long)pid);
	for (i = 0; i < sessions_nalloc; i++) {
		Session *s = &sessions[i];
		if (s->used && s->pid == pid)
			return s;
	}
	error("session_by_pid: unknown pid %ld", (long)pid);
	session_dump();
	return NULL;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.