CAPEC 89

Summary

Attack Execution Flow

1. Attacker sets up a system mocking the one trusted by the users. This is usually a website that requires or handles sensitive information.

2. The attacker then poisons the resolver for the targeted site. This is achieved by poisoning the DNS server, or the local hosts file, that directs the user to the original website

3. When the victim requests the URL for the site, the poisoned records direct the victim to the attacker's system rather than the original one.

4. Because of the identical nature of the original site and the attacker controlled one, and the fact that the URL is still the original one, the victim trusts the website reached and the attacker can now "farm" sensitive information such as credentials or account numbers.

Likelihood: High

Description

Skill or Knowledge Level: Medium

The attacker needs to be able to poison the resolver - DNS entries or local hosts file or router entry pointing to a trusted DNS server - in order to successfully carry out a pharming attack. Setting up a fake website, identical to the targeted one, does not require special skills.

The attacker observes the targeted website for use of secure connection to exchange sensitive information. If it does not use secure connections, victim users cannot distinguish between the original and fake versions of the website.

The attacker can also fingerprint the software running on the targeted system (DNS server, router or host) and look for vulnerabilities in order to poison the entries.

All sensitive infomation must be handled over a secure connection.

Known vulnerabilities in DNS or router software or in operating systems must be patched as soon as a fix has been released and tested.

End users must ensure that they provide sensitive information only to websites that they trust, over a secure connection with a valid certificate issued by a well-known certificate authority.