CWE-296 证书信任链回溯不恰当

Improper Following of a Certificate's Chain of Trust

结构: Simple

Abstraction: Base

状态: Draft

被利用可能性: Low

基本描述

The software does not follow, or incorrectly follows, the chain of trust for a certificate back to a trusted root certificate, resulting in incorrect trust of any resource that is associated with that certificate.

扩展描述

If a system does not follow the chain of trust of a certificate to a root server, the certificate loses all usefulness as a metric of trust. Essentially, the trust gained from a certificate is derived from a chain of trust -- with a reputable trusted entity at the end of that list. The end user must trust that reputable source, and this reputable source must vouch for the resource in question through the medium of the certificate.

In some cases, this trust traverses several entities who vouch for one another. The entity trusted by the end user is at one end of this trust chain, while the certificate-wielding resource is at the other end of the chain. If the user receives a certificate at the end of one of these trust chains and then proceeds to check only that the first link in the chain, no real trust has been derived, since the entire chain must be traversed back to a trusted source to verify the certificate.

There are several ways in which the chain of trust might be broken, including but not limited to:

相关缺陷

  • cwe_Nature: ChildOf cwe_CWE_ID: 295 cwe_View_ID: 1000 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 295 cwe_View_ID: 699 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 573 cwe_View_ID: 1000

适用平台

Language: {'cwe_Class': 'Language-Independent', 'cwe_Prevalence': 'Undetermined'}

常见的影响

范围 影响 注释
Non-Repudiation Hide Activities Exploitation of this flaw can lead to the trust of data that may have originated with a spoofed source.
['Integrity', 'Confidentiality', 'Availability', 'Access Control'] ['Gain Privileges or Assume Identity', 'Execute Unauthorized Code or Commands'] Data, requests, or actions taken by the attacking entity can be carried out as a spoofed benign entity.

可能的缓解方案

Architecture and Design

策略:

Ensure that proper certificate checking is included in the system design.

Implementation

策略:

Understand, and properly implement all checks necessary to ensure the integrity of certificate trust integrity.

Implementation

策略:

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

示例代码

例

This code checks the certificate of a connected peer.

bad C

if ((cert = SSL_get_peer_certificate(ssl)) && host)
foo=SSL_get_verify_result(ssl);

if ((X509_V_OK==foo) || X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN==foo))

// certificate looks good, host can be trusted

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 conducting a man-in-the-middle attack.

分析过的案例

标识 说明 链接
CVE-2016-2402 Server allows bypass of certificate pinning by sending a chain of trust that includes a trusted CA that is not pinned. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2402
CVE-2008-4989 Verification function trusts certificate chains in which the last certificate is self-signed. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-4989
CVE-2012-5821 Chain: Web browser uses a TLS-related function incorrectly, preventing it from verifying that a server's certificate is signed by a trusted certification authority (CA). https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-5821
CVE-2009-3046 Web browser does not check if any intermediate certificates are revoked. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3046
CVE-2009-0265 chain: DNS server does not correctly check return value from the OpenSSL EVP_VerifyFinal function allows bypass of validation of the certificate chain. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-0265
CVE-2009-0124 chain: incorrect check of return value from the OpenSSL EVP_VerifyFinal function allows bypass of validation of the certificate chain. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-0124
CVE-2002-0970 File-transfer software does not validate Basic Constraints of an intermediate CA-signed certificate. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0970
CVE-2002-0862 Cryptographic API, as used in web browsers, mail clients, and other software, does not properly validate Basic Constraints. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0862

分类映射

映射的分类名 ImNode ID Fit Mapped Node Name
CLASP Failure to follow chain of trust in certificate validation

引用