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. 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. 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.
This weakness can occur even when the product uses Certificate Pinning, if the product does not verify the hostname at the time a certificate is pinned.

Primary

Implementation
When the product uses certificate pinning, the developer might not properly validate all relevant components of the certificate before pinning the certificate. This can make it difficult or expensive to test after the pinning is complete.

Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.

High

Access Control
Gain Privileges or Assume Identity
The data read from the system vouched for by the certificate may not be from the expected system.

Authentication
Other
Other
Trust afforded to the system in question - based on the malicious certificate - may allow for spoofing or redirection attacks.

Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
High

Dynamic Analysis with Manual Results Interpretation
Set up an untrusted endpoint (e.g. a server) with which the product will connect. Create a test certificate that uses an invalid hostname but is signed by a trusted CA and provide this certificate from the untrusted endpoint. If the product performs any operations instead of disconnecting and reporting an error, then this indicates that the hostname is not being checked and the test certificate has been accepted.

Black Box
When Certificate Pinning is being used in a mobile application, consider using a tool such as Spinner [REF-955]. This methodology might be extensible to other technologies.

Architecture and Design
Fully check the hostname of the certificate and provide the user with adequate information about the nature of the problem and how to proceed.

Implementation
If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

The following OpenSSL code obtains a certificate and verifies it.

cert = SSL_get_peer_certificate(ssl);if (cert && (SSL_get_verify_result(ssl)==X509_V_OK)) {

// do secret things

}

Even though the "verify" step returns X509_V_OK, this step does not include checking the Common Name against the name of the host. That is, there is no guarantee that the certificate is for the desired host. The SSL connection could have been established with a malicious host that provided a valid certificate.

CVE-2012-5810
Mobile banking application does not verify hostname, leading to financial loss.
https://www.cve.org/CVERecord?id=CVE-2012-5810

CVE-2012-5811
Mobile application for printing documents does not verify hostname, allowing attackers to read sensitive documents.
https://www.cve.org/CVERecord?id=CVE-2012-5811

CVE-2012-5807
Software for electronic checking does not verify hostname, leading to financial loss.
https://www.cve.org/CVERecord?id=CVE-2012-5807

CVE-2012-3446
Cloud-support library written in Python uses incorrect regular expression when matching hostname.
https://www.cve.org/CVERecord?id=CVE-2012-3446

CVE-2009-2408
Web browser does not correctly handle '\0' character (NUL) in Common Name, allowing spoofing of https sites.
https://www.cve.org/CVERecord?id=CVE-2009-2408

CVE-2012-0867
Database program truncates the Common Name during hostname verification, allowing spoofing.
https://www.cve.org/CVERecord?id=CVE-2012-0867

CVE-2010-2074
Incorrect handling of '\0' character (NUL) in hostname verification allows spoofing.
https://www.cve.org/CVERecord?id=CVE-2010-2074

CVE-2009-4565
Mail server's incorrect handling of '\0' character (NUL) in hostname verification allows spoofing.
https://www.cve.org/CVERecord?id=CVE-2009-4565

CVE-2009-3767
LDAP server's incorrect handling of '\0' character (NUL) in hostname verification allows spoofing.
https://www.cve.org/CVERecord?id=CVE-2009-3767

CVE-2012-5806
Payment processing module does not verify hostname when connecting to PayPal using PHP fsockopen function.
https://www.cve.org/CVERecord?id=CVE-2012-5806

CVE-2012-2993
Smartphone device does not verify hostname, allowing spoofing of mail services.
https://www.cve.org/CVERecord?id=CVE-2012-2993

CVE-2012-5804
E-commerce module does not verify hostname when connecting to payment site.
https://www.cve.org/CVERecord?id=CVE-2012-5804

CVE-2012-5824
Chat application does not validate hostname, leading to loss of privacy.
https://www.cve.org/CVERecord?id=CVE-2012-5824

CVE-2012-5822
Application uses third-party library that does not validate hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5822

CVE-2012-5819
Cloud storage management application does not validate hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5819

CVE-2012-5817
Java library uses JSSE SSLSocket and SSLEngine classes, which do not verify the hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5817

CVE-2012-5784
SOAP platform does not verify the hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5784

CVE-2012-5782
PHP library for payments does not verify the hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5782

CVE-2012-5780
Merchant SDK for payments does not verify the hostname.
https://www.cve.org/CVERecord?id=CVE-2012-5780

CVE-2003-0355
Web browser does not validate Common Name, allowing spoofing of https sites.
https://www.cve.org/CVERecord?id=CVE-2003-0355

Failure to validate host-specific certificate data

Allowed
This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

CLASP
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings

CWE Content Team
MITRE
2009-03-10
updated Description, Name, Relationships

CWE Content Team
MITRE
2009-05-27
updated Demonstrative_Examples

CWE Content Team
MITRE
2009-07-27
updated Demonstrative_Examples, Relationships

CWE Content Team
MITRE
2010-12-13
updated Description, Other_Notes

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated References, Relationships

CWE Content Team
MITRE
2013-02-21
updated Applicable_Platforms, Demonstrative_Examples, Description, Name, Observed_Examples, References, Relationships, Type

CWE Content Team
MITRE
2013-07-17
updated Relationships

CWE Content Team
MITRE
2014-07-30
updated Relationships

CWE Content Team
MITRE
2015-12-07
updated Relationships

CWE Content Team
MITRE
2017-11-08
updated Demonstrative_Examples, Modes_of_Introduction, References, Relationships

CWE Content Team
MITRE
2018-01-16
Integrated mitigations and detection methods for Certificate Pinning based on feedback from the CWE Researcher List in December 2017.

CWE Content Team
MITRE
2018-03-27
updated Common_Consequences, Description, Detection_Factors, Modes_of_Introduction, Potential_Mitigations, References, Time_of_Introduction

CWE Content Team
MITRE
2019-06-20
updated Relationships

CWE Content Team
MITRE
2019-09-19
updated Demonstrative_Examples

CWE Content Team
MITRE
2020-02-24
updated Applicable_Platforms, References, Relationships

CWE Content Team
MITRE
2021-10-28
updated Relationships

CWE Content Team
MITRE
2022-10-13
updated References

CWE Content Team
MITRE
2023-01-31
updated Applicable_Platforms, Description, Detection_Factors, Modes_of_Introduction

CWE Content Team
MITRE
2023-04-27
updated Detection_Factors, References, Relationships, Time_of_Introduction

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-09-09
4.18
2025-09-09
updated References

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Applicable_Platforms, Relationships, Weakness_Ordinalities

Failure to Validate Host-specific Certificate Data
Improper Validation of Host-specific Certificate Data