CWE-350

Reliance on Reverse DNS Resolution for a Security-Critical Action
AI Translation Available

The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname.

Status
draft
Abstraction
variant

Since DNS names can be easily spoofed or misreported, and it may be difficult for the product to detect if a trusted DNS server has been compromised, DNS names do not constitute a valid authentication mechanism.

When the product performs a reverse DNS resolution for an IP address, if an attacker controls the DNS server for that IP address, then the attacker can cause the server to return an arbitrary hostname. As a result, the attacker may be able to bypass authentication, cause the wrong hostname to be recorded in log files to hide activities, or perform other attacks.

Attackers can spoof DNS names by either (1) compromising a DNS server and modifying its records (sometimes called DNS cache poisoning), or (2) having legitimate control over a DNS server associated with their IP address.

Common Consequences

access control
Impacts
gain privileges or assume identity bypass protection mechanism

Detection Methods

automated static analysis

Potential Mitigations

Phases:
architecture and design implementation
Descriptions:
• Perform proper forward and reverse DNS lookups to detect DNS spoofing.
• Use other means of identity verification that cannot be simply spoofed. Possibilities include a username/password or certificate.