OpenMage magento-lts before 20.18.2 and 21.x before 21.0.0-beta3 validates OAuth 1.0a oauthcallback URLs with a string-prefix check and falls back to accepting any well-formed URL. Attackers holding a leaked consumer key and secret can supply host-suffix, userinfo, or arbitrary callback URLs to capture an approving administrator's or customer's request token and verifier, then obtain an access token with the victim's API privileges.

OpenMage Magento-LTS before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 contains an authorization bypass in the /rss/order/status feed because its URL key is unsigned Base64-encoded JSON of the order, increment, and customer ids. Unauthenticated attackers can forge keys from enumerated sequential ids to read other customers' names, items, prices, totals, and status comments when order-status RSS is enabled.

OpenMage magento-lts before 20.18.2 and 21.0.0-beta pre-releases before 21.0.0-beta3 generate customer email-confirmation keys with md5(uniqid()) and customer and administrator password-reset tokens with the non-cryptographic uniqHash(). Unauthenticated attackers can brute-force the roughly 20-bit confirmation key via the unrate-limited confirmAction endpoint to log in as pending customers, or predict administrator reset tokens after recovering generator state.

OpenMage magento-lts before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 lets restricted administrators read decrypted configuration secrets because the store.getConfig email template directive's encrypted-path check missed config.xml-declared paths, case variants of the getConfig method name, and parent paths. Administrators with Transactional Emails access can preview a crafted template to expose PayPal, payment gateway, and carrier credentials.