Improper Certificate Validation
The software does not validate, or incorrectly validates, a certificate.
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The software might connect to a malicious host while believing it is a trusted host, or the software might be deceived into accepting spoofed data that appears to originate from a trusted host.
A certificate is a token that associates an identity (principal) to a cryptographic key. Certificates can be used to check if a public key belongs to the assumed owner.
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
This code checks the certificate of a connected peer.
In this case, because the certificate is self-signed, there was no external authority that could prove the identity of the host. The program could be communicating with a different system that is spoofing the host, e.g. by poisoning the DNS cache or using an Adversary-in-the-Middle (AITM) attack to modify the traffic from server to client.
The following OpenSSL code obtains a certificate and verifies it.
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.
The following OpenSSL code ensures that there is a certificate and allows the use of expired certificates.
If the call to SSL_get_verify_result() returns X509_V_ERR_CERT_HAS_EXPIRED, this means that the certificate has expired. As time goes on, there is an increasing chance for attackers to compromise the certificate.
The following OpenSSL code ensures that there is a certificate before continuing execution.
Because this code does not use SSL_get_verify_results() to check the certificate, it could accept certificates that have been revoked (X509_V_ERR_CERT_REVOKED). The software could be communicating with a malicious host.
The following OpenSSL code ensures that the host has a certificate.
Note that the code does not call SSL_get_verify_result(ssl), which effectively disables the validation step that checks the certificate.
Weaknesses in this category are related to the "Emerging Energy Technologies" category from the SEI ETF "Categories of Security Vulnerabilities in ICS" as published in...
Weaknesses in this category are related to the A07 category "Identification and Authentication Failures" in the OWASP Top Ten 2021.
Weaknesses in this category are related to authentication components of a system. Frequently these deal with the ability to verify that an entity is indeed who it clai...
This view (slice) covers all the elements in CWE.
CWE entries in this view are listed in the 2019 CWE Top 25 Most Dangerous Software Errors.
CWE identifiers in this view are weaknesses that do not have associated Software Fault Patterns (SFPs), as covered by the CWE-888 view. As such, they represent gaps in...