Due to missing authorization checks, any authenticated user is able to list, upload, or delete attachments to password safe entries in Pleasant Password Server before 7.8.3. To perform those actions on an entry, the user needs to know the corresponding "CredentialId" value, which uniquely identifies a password safe entry. Since "CredentialId" values are implemented as GUIDs, they are hard to guess. However, if for example an entry's owner grants read-only access to a malicious user, the value gets exposed to the malicious user. The same holds true for temporary grants.