CWE-297βImproper Validation of Certificate with Host Mismatch
PUBLISHEDweakness recordHigh
released 2006-07-19 Β· last modified 2026-04-30
Metadata
- CWE ID:
- CWE-297
- Abstraction:
- Variant
- Structure:
- Simple
- Status:
- Incomplete
- Release Date:
- 2006-07-19
- Latest Modification Date:
- 2026-04-30
Weakness Name
Improper Validation of Certificate with Host Mismatch
Description
The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.
Even if a certificate is well-formed, signed, and follows the chain of trust, it may simply be a valid certificate for a different site than the site that the product is interacting with. In order to ensure data integrity, the certificate must be valid, and it must pertain to the site that is being accessed. Even if the product attempts to check the hostname, it is still possible to incorrectly check the hostname. For example, attackers could create a certificate with a name that begins with a trusted name followed by a NUL byte, which could cause some string-based comparisons to only examine the portion that contains the trusted name.
Common Consequences
- Scope:
- Access Control
- Impact:
- Gain Privileges or Assume Identity
- Notes:
- The data read from the system vouched for by the certificate may not be from the expected system.
- Scope:
- Authentication, Other
- Impact:
- Other
- Notes:
- Trust afforded to the system in question - based on the malicious certificate - may allow for spoofing or redirection attacks.
- Scope:
- Access Control, Other
- Impact:
- Gain Privileges or Assume Identity, Other
- Notes:
- If the certificate's host-specific data is not properly checked - such as the Common Name (CN) in the Subject or the Subject Alternative Name (SAN) extension of an X.509 certificate - it may be possible for a redirection or spoofing attack to allow a malicious host with a valid certificate to provide data, impersonating a trusted host.
