NivoCart through 2.5.1 contains a CAPTCHA bypass vulnerability that allows unauthenticated attackers to defeat form protection because the expected code is printed as plain text in the HTML. Attackers can fetch protected forms, extract the captchaimage value with a pattern match, and submit it to automate spam, registrations, reviews, and account deletion requests.

NivoCart through 2.5.1 contains a missing authorization vulnerability in the download() action of account/order that allows unauthenticated attackers to retrieve guest order invoices by supplying an orderid. Attackers can iterate the orderid parameter, which matches guest orders stored with customerid 0, to disclose guest names, addresses, telephone numbers, emails, purchased items, and totals.