An existing abuse of functionality in the "Check for mail using POP3"
capability permits automated attacks to the password data of the
accounts of the Gmail users evading the security measures adopted by
Gmail implements a great number of security controls and, most of them
are not revealed until an attack is conducted or a malicious use of
the account is done. For example:
- Use of catpcha for avoiding automated processes (e.g., in the users
authentication or in the new users sign up).
- Temporary IP locking in case of detecting unusual application
activities (e.g., multiple new account creation requests)
- Temporary account locking in case of detecting unusual use of the
user account (e.g., when doing multiple consecutive request to the
- Detection of concurrent access to the account from different
geolocated IP addresses added to the number of these accesses.
Anyway, is it possible to abuse the "Check for mail using POP3"
capability to do attacks to the passwords of the users in an automated
way, evading all referred security restrictions and controls and doing
a transparent and not noticeable attack to the user that its account
is being password cracked as:
- There's no need for required action from the victim.
- There's no modification in the password of the victim.
- There's no locking in the victim account.
- There's no security notification to the victim.
See More Info and Poc.
Possible link to Twitter hack – GMail vulnerable to password cracking