CWE -
CWE-295: Improper Certificate Validation (4.20) ([original](http://cwe.mitre.org/data/definitions/295.html)) ([raw](?raw))| CWE Glossary Definition |  |
|---|---|
Weakness ID: 295
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction:Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
Description
| The product does not validate, or incorrectly validates, a certificate. |  |
|---|
Common Consequences
This table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
| Impact | Details |
|---|---|
| Bypass Protection Mechanism; Gain Privileges or Assume Identity | Scope: Integrity, Authentication 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 product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host. |
Potential Mitigations
| Phase(s) | Mitigation |
|---|---|
| Architecture and Design; Implementation | Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key. |
| 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. |
Relationships
This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
Relevant to the view "Research Concepts" (View-1000)
| Nature | Type | ID | Name |
|---|---|---|---|
| ChildOf |  Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. |
287 | Improper Authentication |
| ParentOf |  Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
296 | Improper Following of a Certificate's Chain of Trust |
| ParentOf |  Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. |
297 | Improper Validation of Certificate with Host Mismatch |
| ParentOf | Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. |
298 | Improper Validation of Certificate Expiration |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
299 | Improper Check for Certificate Revocation |
| ParentOf | Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. |
599 | Missing Validation of OpenSSL Certificate |
| PeerOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
322 | Key Exchange without Entity Authentication |
Relevant to the view "Software Development" (View-699)
| Nature | Type | ID | Name |
|---|---|---|---|
| MemberOf |  Category - a CWE entry that contains a set of other entries that share a common characteristic. |
1211 | Authentication Errors |
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-1003)
| Nature | Type | ID | Name |
|---|---|---|---|
| ChildOf | Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. |
287 | Improper Authentication |
Relevant to the view "Architectural Concepts" (View-1008)
| Nature | Type | ID | Name |
|---|---|---|---|
| MemberOf | Category - a CWE entry that contains a set of other entries that share a common characteristic. |
1014 | Identify Actors |
Background Details
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.
Modes Of Introduction
The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
| Phase | Note |
|---|---|
| Architecture and Design | |
| Implementation | REALIZATION: This weakness is caused during implementation of an architectural security tactic. |
| 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. |
Applicable Platforms
This listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.
| Languages | Class: Not Language-Specific(Undetermined Prevalence) |
|---|---|
| Technologies | Class: Not Technology-Specific(Undetermined Prevalence) Class: Web Based(Undetermined Prevalence) Class: Mobile(Undetermined Prevalence) |
Demonstrative Examples
Example 1
This code checks the certificate of a connected peer.
(bad code)
Example Language: 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 using an Adversary-in-the-Middle (AITM) attack to modify the traffic from server to client.
Example 2
The following OpenSSL code obtains a certificate and verifies it.
(bad code)
Example Language: C
cert = SSL_get_peer_certificate(ssl);
if (cert && (SSL_get_verify_result(ssl)==X509_V_OK)) {
}
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.
Example 3
The following OpenSSL code ensures that there is a certificate and allows the use of expired certificates.
(bad code)
Example Language: C
if (cert = SSL_get_peer(certificate(ssl)) {
foo=SSL_get_verify_result(ssl);
if ((X509_V_OK==foo) || (X509_V_ERR_CERT_HAS_EXPIRED==foo))
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.
Example 4
The following OpenSSL code ensures that there is a certificate before continuing execution.
(bad code)
Example Language: C
if (cert = SSL_get_peer_certificate(ssl)) {
// got a certificate, do secret things
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.
Example 5
The following OpenSSL code ensures that the host has a certificate.
(bad code)
Example Language: C
if (cert = SSL_get_peer_certificate(ssl)) {
// got certificate, host can be trusted
//foo=SSL_get_verify_result(ssl);
//if (X509_V_OK==foo) ...
}
Note that the code does not call SSL_get_verify_result(ssl), which effectively disables the validation step that checks the certificate.
Selected Observed Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
| Reference | Description |
|---|---|
| CVE-2019-12496 | A Go framework for robotics, drones, and IoT devices skips verification of root CA certificates by default. |
| CVE-2014-1266 | Chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing Adversary-in-the-Middle (AITM) attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-561 (Dead Code) -> CWE-295 (Improper Certificate Validation) -> CWE-393 (Return of Wrong Status Code) -> CWE-300 (Channel Accessible by Non-Endpoint). The code's whitespace indentation did not reflect the actual control flow (CWE-1114) and did not explicitly delimit the block (CWE-483), which could have made it more difficult for human code auditors to detect the vulnerability. |
| CVE-2021-22909 | Chain: router's firmware update procedure uses curl with "-k" (insecure) option that disables certificate validation (CWE-295), allowing adversary-in-the-middle (AITM) compromise with a malicious firmware image (CWE-494). |
| CVE-2008-4989 | Verification function trusts certificate chains in which the last certificate is self-signed. |
| CVE-2012-5821 | 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) |
| CVE-2009-3046 | Web browser does not check if any intermediate certificates are revoked. |
| CVE-2011-0199 | Operating system does not check Certificate Revocation List (CRL) in some cases, allowing spoofing using a revoked certificate. |
| CVE-2012-5810 | Mobile banking application does not verify hostname, leading to financial loss. |
| CVE-2012-3446 | Cloud-support library written in Python uses incorrect regular expression when matching hostname. |
| CVE-2009-2408 | Web browser does not correctly handle '\0' character (NUL) in Common Name, allowing spoofing of https sites. |
| CVE-2012-2993 | Smartphone device does not verify hostname, allowing spoofing of mail services. |
| CVE-2012-5822 | Application uses third-party library that does not validate hostname. |
| CVE-2012-5819 | Cloud storage management application does not validate hostname. |
| CVE-2012-5817 | Java library uses JSSE SSLSocket and SSLEngine classes, which do not verify the hostname. |
| CVE-2010-1378 | Chain: incorrect calculation (CWE-682) allows attackers to bypass certificate checks (CWE-295) |
| CVE-2007-6746 | library for SSL and TLS does not check the activation or expiration dates of CA certificates |
| CVE-2005-3170 | LDAP client accepts certificates even if they are not from a trusted CA. |
| 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. |
| CVE-2003-1229 | chain: product checks if client is trusted when it intended to check if the server is trusted, allowing validation of signed code. |
| CVE-2002-0862 | Cryptographic API, as used in web browsers, mail clients, and other software, does not properly validate Basic Constraints. |
| CVE-2009-1358 | chain: OS package manager does not check properly check the return value, allowing bypass using a revoked certificate. |
Weakness Ordinalities
| Ordinality | Description |
|---|---|
| Primary | (where the weakness exists independent of other weaknesses) |
Detection Methods
| Method | Details |
|---|---|
| Automated Static Analysis - Binary or Bytecode | According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis Effectiveness: SOAR Partial |
| Manual Static Analysis - Binary or Bytecode | According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies Effectiveness: SOAR Partial |
| Dynamic Analysis with Automated Results Interpretation | According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Web Application Scanner Effectiveness: SOAR Partial |
| Dynamic Analysis with Manual Results Interpretation | According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Man-in-the-middle attack tool Effectiveness: High |
| Manual Static Analysis - Source Code | According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Focused Manual Spotcheck - Focused manual analysis of source Manual Source Code Review (not inspections) Effectiveness: High |
| Automated Static Analysis - Source Code | According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer Effectiveness: SOAR Partial |
| Architecture or Design Review | According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.) Effectiveness: High |
Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
Vulnerability Mapping Notes
| Usage | ALLOWED (this CWE ID may be used to map to real-world vulnerabilities) |
|---|---|
| Reason | Acceptable-Use |
| Rationale | This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities. |
| Comments | 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. |
Taxonomy Mappings
| Mapped Taxonomy Name | Node ID | Fit | Mapped Node Name |
|---|---|---|---|
| OWASP Top Ten 2004 | A10 | CWE More Specific | Insecure Configuration Management |
References
Content History
| Submissions |
||
|---|---|---|
| Submission Date | Submitter | Organization |
| 2006-07-19(CWE Draft 3, 2006-07-19) | CWE Community | |
| Submitted by members of the CWE community to extend early CWE versions | ||
 Modifications |
||
| Modification Date | Modifier | Organization |
| 2026-04-30(CWE 4.20, 2026-04-30) | CWE Content Team | MITRE |
| updated Observed_Examples | ||
| 2025-12-11(CWE 4.19, 2025-12-11) | CWE Content Team | MITRE |
| updated Applicable_Platforms, Observed_Examples, Relationships, Weakness_Ordinalities | ||
| 2025-09-09(CWE 4.18, 2025-09-09) | CWE Content Team | MITRE |
| updated Common_Consequences, Description, Detection_Factors, Diagram, References | ||
| 2023-06-29(CWE 4.12, 2023-06-29) | CWE Content Team | MITRE |
| updated Mapping_Notes | ||
| 2023-04-27(CWE 4.11, 2023-04-27) | CWE Content Team | MITRE |
| updated Relationships | ||
| 2023-01-31(CWE 4.10, 2023-01-31) | CWE Content Team | MITRE |
| updated Description, Modes_of_Introduction | ||
| 2022-10-13(CWE 4.9, 2022-10-13) | CWE Content Team | MITRE |
| updated Observed_Examples, References | ||
| 2022-04-28(CWE 4.7, 2022-04-28) | CWE Content Team | MITRE |
| updated Relationships | ||
| 2021-10-28(CWE 4.6, 2021-10-28) | CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
| 2021-07-20(CWE 4.5, 2021-07-20) | CWE Content Team | MITRE |
| updated Demonstrative_Examples, Observed_Examples | ||
| 2020-08-20(CWE 4.2, 2020-08-20) | CWE Content Team | MITRE |
| updated Related_Attack_Patterns | ||
| 2020-02-24(CWE 4.0, 2020-02-24) | CWE Content Team | MITRE |
| updated Applicable_Platforms, Demonstrative_Examples, Description, Observed_Examples, Relationships | ||
| 2019-09-19(CWE 3.4, 2019-09-19) | CWE Content Team | MITRE |
| updated Demonstrative_Examples, Relationships | ||
| 2019-06-20(CWE 3.3, 2019-06-20) | CWE Content Team | MITRE |
| updated Relationships | ||
| 2018-03-27(CWE 3.1, 2018-03-27) | CWE Content Team | MITRE |
| updated Background_Details, Modes_of_Introduction, Potential_Mitigations, Relationships | ||
| 2017-11-08(CWE 3.0, 2017-11-08) | CWE Content Team | MITRE |
| updated Modes_of_Introduction, References, Relationships | ||
| 2017-01-19(CWE 2.10, 2017-01-19) | CWE Content Team | MITRE |
| updated Relationships | ||
| 2015-12-07(CWE 2.9, 2015-12-07) | CWE Content Team | MITRE |
| updated Relationships | ||
| 2014-07-30(CWE 2.8, 2014-07-31) | CWE Content Team | MITRE |
| updated Detection_Factors | ||
| 2014-06-23(CWE 2.7, 2014-06-23) | CWE Content Team | MITRE |
| updated Observed_Examples | ||
| 2013-02-21(CWE 2.4, 2013-02-21) | CWE Content Team | MITRE |
| updated Applicable_Platforms, Common_Consequences, Description, Name, Observed_Examples, Potential_Mitigations, References, Relationships, Time_of_Introduction, Type | ||
| 2012-12-28(CWE 2.4, 2013-02-21) | CWE Content Team | MITRE |
| Converted from category to weakness class. | ||
| 2012-05-11(CWE 2.2, 2012-05-15) | CWE Content Team | MITRE |
| updated Related_Attack_Patterns | ||
| 2008-10-14(CWE 1.0.1, 2008-10-14) | CWE Content Team | MITRE |
| updated Background_Details, Description | ||
| 2008-09-08(CWE 1.0, 2008-09-09) | CWE Content Team | MITRE |
| updated Relationships, Taxonomy_Mappings | ||
| 2008-08-15(CWE 1.0, 2008-09-09) | Veracode | |
| Suggested OWASP Top Ten 2004 mapping | ||
| Previous Entry Names |
||
| Change Date | Previous Entry Name | |
| 2013-02-21 | Certificate Issues |
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