1. SECURITY FIX: Validate useridLength to prevent Loop DoS and buffer overflow

• VM userids in z/VM are maximum 8 characters
• cacheUserID buffer is only 9 bytes (8 + 1 for null terminator) ----> char cacheUserID[ 8 + 1 ];

Without this check, an attacker could:

• Send useridLength=0xFFFFFFFF causing the below for loop to run billions of times (Loop DoS)
• Send useridLength>8 causing buffer overflow in cacheUserID

                for (x = 0; x < useridLength; ++x) {
                    cacheUserID[x] = tolower(userid[x]);
                }

2. Fix Path/Directory Traversal to prevents attacks like "/valid/path/../../../etc