QloApps through 1.7.0, fixed in commit 64e9722, contains a weak cryptographic algorithm vulnerability that allows attackers to compromise user credentials by exploiting the use of MD5 for password hashing in the Tools::encrypt() function within classes/Tools.php, which concatenates a static cookie key with the supplied password. Attackers can perform offline brute-force attacks against the MD5 hashes, with the risk compounded by auto-generated 8-character passwords assigned during guest-to-customer account conversion in classes/Customer.php, making credential recovery trivial.