A vulnerability in the Cisco SD-WAN Solution could allow an unauthenticated, remote attacker to bypass certificate validation on an affected device. The vulnerability is due to improper certificate validation. An attacker could exploit this vulnerability by supplying a system image signed with a crafted certificate to an affected device, bypassing the certificate validation. An exploit could allow an attacker to deploy a crafted system image.

A vulnerability in the Secure Sockets Layer (SSL) Virtual Private Network (VPN) Client Certificate Authentication feature for Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to establish an SSL VPN connection and bypass certain SSL certificate verification steps. The vulnerability is due to incorrect verification of the SSL Client Certificate. An attacker could exploit this vulnerability by connecting to the ASA VPN without a proper private key and certificate pair. A successful exploit could allow the attacker to establish an SSL VPN connection to the ASA when the connection should have been rejected. This vulnerability affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliances (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliances (ASAv), Firepower 4110 Security Appliances, Firepower 9300 ASA Security Modules. Cisco Bug IDs: CSCvg40155.

A vulnerability in the Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) certificate validation during EAP authentication for the Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the ISE application server to restart unexpectedly, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to incomplete input validation of the client EAP-TLS certificate. An attacker could exploit this vulnerability by initiating EAP authentication over TLS to the ISE with a crafted EAP-TLS certificate. A successful exploit could allow the attacker to restart the ISE application server, resulting in a DoS condition on the affected system. The ISE application could continue to restart while the client attempts to establish the EAP authentication connection. If an attacker attempted to import the same EAP-TLS certificate to the ISE trust store, it could trigger a DoS condition on the affected system. This exploit vector would require the attacker to have valid administrator credentials. The vulnerability affects Cisco ISE, Cisco ISE Express, and Cisco ISE Virtual Appliance. Cisco Bug IDs: CSCve31857.

Improper Certificate Validation in Checkmk Exchange plugin MikroTik allows attackers in MitM position to intercept traffic. This issue affects MikroTik: from 2.0.0 through 2.5.5, from 0.4a_mk through 2.0a.

The Certificate Trust Policy component in Apple Mac OS X before 10.6.8 does not perform CRL checking for Extended Validation (EV) certificates that lack OCSP URLs, which might allow man-in-the-middle attackers to spoof an SSL server via a revoked certificate.

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.6.1, Traefik skips the router transport layer security (TLS) configuration when the host header is a fully qualified domain name (FQDN). For a request, the TLS configuration choice can be different than the router choice, which implies the use of a wrong TLS configuration. When sending a request using FQDN handled by a router configured with a dedicated TLS configuration, the TLS configuration falls back to the default configuration that might not correspond to the configured one. If the CNAME flattening is enabled, the selected TLS configuration is the SNI one and the routing uses the CNAME value, so this can skip the expected TLS configuration. Version 2.6.1 contains a patch for this issue. As a workaround, one may add the FDQN to the host rule. However, there is no workaround if the CNAME flattening is enabled.

lib/oauth/consumer.rb in the oauth-ruby gem through 0.5.4 for Ruby does not verify server X.509 certificates if a certificate bundle cannot be found, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information.

Jenkins Mailer Plugin 1.32 and earlier does not perform hostname validation when connecting to the configured SMTP server.

An improper certificate validation vulnerability exists in the BIG-IP Edge Client for Windows and macOS and may allow an attacker to impersonate a BIG-IP APM system.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Jenkins Email Extension Plugin 2.75 and earlier does not perform hostname validation when connecting to the configured SMTP server.

Incorrect validation of the TLS SNI hostname in osquery versions after 2.9.0 and before 4.2.0 could allow an attacker to MITM osquery traffic in the absence of a configured root chain of trust.

A vulnerability exists in the component RTU500 Scripting interface. When a client connects to a server using TLS, the server presents a certificate. This certificate links a public key to the identity of the service and is signed by a Certification Authority (CA), allowing the client to validate that the remote service can be trusted and is not malicious. If the client does not validate the parameters of the certificate, then attackers could be able to spoof the identity of the service. An attacker could exploit the vulnerability by using faking the identity of a RTU500 device and intercepting the messages initiated via the RTU500 Scripting interface.

Improper Certificate Validation in GitHub repository pyload/pyload prior to 0.5.0b3.dev44.

In faye-websocket before version 0.11.0, there is a lack of certification validation in TLS handshakes. The `Faye::WebSocket::Client` class uses the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname. That means that any `wss:` connection made using this library is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. For further background information on this issue, please see the referenced GitHub Advisory. Upgrading `faye-websocket` to v0.11.0 is recommended.

Missing validation of server certificates for out-going connections in Nextcloud Social < 0.4.0 allowed a man-in-the-middle attack.

The komoot GmbH "Komoot - Cycling & Hiking Maps" app before 9.3.2 -- aka komoot-cycling-hiking-maps/id447374873 -- for iOS does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Serverpod is an app and web server, built for the Flutter and Dart ecosystem. This bug bypassed the validation of TSL certificates on all none web HTTP clients in the `serverpod_client` package. Making them susceptible to a man in the middle attack against encrypted traffic between the client device and the server. An attacker would need to be able to intercept the traffic and highjack the connection to the server for this vulnerability to be used. Upgrading to version `1.2.6` resolves this issue.

Android App 'MyPallete' and some of the Android banking applications based on 'MyPallete' do not verify X.509 certificates from servers, and also do not properly validate certificates with host-mismatch, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

A vulnerability exists in the FOXMAN-UN/UNEM server that affects the message queueing mechanism’s certificate validation. If exploited an attacker could spoof a trusted entity causing a loss of confidentiality and integrity.

A flaw was found in all Openshift Enterprise versions using the openshift elasticsearch plugin. An attacker with knowledge of the given name used to authenticate and access Elasticsearch can later access it without the token, bypassing authentication. This attack also requires that the Elasticsearch be configured with an external route, and the data accessed is limited to the indices.

Due to improper validation of certificate in SAP Cloud Connector - version 2.0, attacker can impersonate the genuine servers to interact with SCC breaking the mutual authentication. Hence, the attacker can intercept the request to view/modify sensitive information. There is no impact on the availability of the system.

A vulnerability has been identified in Industrial Edge Management (All versions < V1.5.1). The affected software does not properly validate the server certificate when initiating a TLS connection. This could allow an attacker to spoof a trusted entity by interfering in the communication path between the client and the intended server.

An improper certificate validation vulnerability [CWE-295] in FortiOS 7.2.0 through 7.2.3, 7.0.0 through 7.0.7, 6.4 all versions, 6.2 all versions, 6.0 all versions and FortiProxy 7.0.0 through 7.0.6, 2.0 all versions, 1.2 all versions may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the FortiOS/FortiProxy device and remote servers hosting threat feeds (when the latter are configured as Fabric connectors in FortiOS/FortiProxy)

When using Ingest Actions to configure a destination that resides on Amazon Simple Storage Service (S3) in Splunk Web, TLS certificate validation is not correctly performed and tested for the destination. The vulnerability only affects connections between Splunk Enterprise and an Ingest Actions Destination through Splunk Web and only applies to environments that have configured TLS certificate validation. It does not apply to Destinations configured directly in the outputs.conf configuration file. The vulnerability affects Splunk Enterprise version 9.0.0 and does not affect versions below 9.0.0, including the 8.1.x and 8.2.x versions.

In Splunk Enterprise and Universal Forwarder versions before 9.0, the Splunk command-line interface (CLI) did not validate TLS certificates while connecting to a remote Splunk platform instance by default. After updating to version 9.0, see Configure TLS host name validation for the Splunk CLI https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation#Configure_TLS_host_name_validation_for_the_Splunk_CLI to enable the remediation. The vulnerability does not affect the Splunk Cloud Platform. At the time of publishing, we have no evidence of exploitation of this vulnerability by external parties. The issue requires conditions beyond the control of a potential bad actor such as a machine-in-the-middle attack. Hence, Splunk rates the complexity of the attack as High.

Accepting arbitrary Subject Alternative Name (SAN) types, unless a PKI is specifically defined to use a particular SAN type, can result in bypassing name-constrained intermediates. Node.js < 12.22.9, < 14.18.3, < 16.13.2, and < 17.3.1 was accepting URI SAN types, which PKIs are often not defined to use. Additionally, when a protocol allows URI SANs, Node.js did not match the URI correctly.Versions of Node.js with the fix for this disable the URI SAN type when checking a certificate against a hostname. This behavior can be reverted through the --security-revert command-line option.

Apache Sling Commons Messaging Mail provides a simple layer on top of JavaMail/Jakarta Mail for OSGi to send mails via SMTPS. To reduce the risk of "man in the middle" attacks additional server identity checks must be performed when accessing mail servers. For compatibility reasons these additional checks are disabled by default in JavaMail/Jakarta Mail. The SimpleMailService in Apache Sling Commons Messaging Mail 1.0 lacks an option to enable these checks for the shared mail session. A user could enable these checks nevertheless by accessing the session via the message created by SimpleMessageBuilder and setting the property mail.smtps.ssl.checkserveridentity to true. Apache Sling Commons Messaging Mail 2.0 adds support for enabling server identity checks and these checks are enabled by default. - https://javaee.github.io/javamail/docs/SSLNOTES.txt - https://javaee.github.io/javamail/docs/api/com/sun/mail/smtp/package-summary.html - https://github.com/eclipse-ee4j/mail/issues/429

e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.

A vulnerability has been discovered in Bitdefender Total Security HTTPS scanning functionality that results in the improper trust of certificates issued using the DSA signature algorithm. The product does not properly check the certificate chain, allowing an attacker to establish MITM SSL connections to arbitrary sites using a DSA-signed certificate.

niconico App for iOS before 6.38 does not verify SSL certificates which could allow remote attackers to execute man-in-the-middle attacks.

The Thycotic Password Manager Secret Server application through 2.3 for iOS does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

A vulnerability has been discovered in Bitdefender Total Security HTTPS scanning functionality that results in the improper trust of self-signed certificates. The product is found to trust certificates signed with the RIPEMD-160 hashing algorithm without proper validation, allowing an attacker to establish MITM SSL connections to arbitrary sites.

Rakuten card App for iOS 5.2.0 through 5.2.4 does not verify SSL certificates which might allow remote attackers to execute man-in-the-middle attacks.

OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.

A vulnerability has been identified in Bitdefender Total Security HTTPS scanning functionality where the software fails to properly validate website certificates. Specifically, if a site certificate lacks the "Server Authentication" specification in the Extended Key Usage extension, the product does not verify the certificate's compliance with the site, deeming such certificates as valid. This flaw could allow an attacker to perform a Man-in-the-Middle (MITM) attack, intercepting and potentially altering communications between the user and the website.

The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a "purpose" has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named "purpose" values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1h-1.1.1j).

A flaw was found in the python-scciclient when making an HTTPS connection to a server where the server's certificate would not be verified. This issue opens up the connection to possible Man-in-the-middle (MITM) attacks.

An improper certificate validation vulnerability [CWE-295] in FortiADC 7.4.0, 7.2.0 through 7.2.3, 7.1 all versions, 7.0 all versions, 6.2 all versions, 6.1 all versions and 6.0 all versions may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the device and various remote servers such as private SDN connectors and FortiToken Cloud.

A vulnerability has been identified in Bitdefender Total Security HTTPS scanning functionality where the software trusts a certificate issued by an entity that isn't authorized to issue certificates. This occurs when the "Basic Constraints" extension in the certificate indicates that it is meant to be an "End Entity”. This flaw could allow an attacker to perform a Man-in-the-Middle (MITM) attack, intercepting and potentially altering communications between the user and the website.

The AWV component of Mitel MiCollab before 9.3 could allow an attacker to perform a Man-In-the-Middle attack due to improper TLS negotiation. A successful exploit could allow an attacker to view and modify data.

Missing SSL certificate validation in localstack v2.3.2 allows attackers to eavesdrop on communications between the host and server via a man-in-the-middle attack.

WP-CLI is the command-line interface for WordPress. An improper error handling in HTTPS requests management in WP-CLI version 0.12.0 and later allows remote attackers able to intercept the communication to remotely disable the certificate verification on WP-CLI side, gaining full control over the communication content, including the ability to impersonate update servers and push malicious updates towards WordPress instances controlled by the vulnerable WP-CLI agent, or push malicious updates toward WP-CLI itself. The vulnerability stems from the fact that the default behavior of `WP_CLI\Utils\http_request()` when encountering a TLS handshake error is to disable certificate validation and retry the same request. The default behavior has been changed with version 2.5.0 of WP-CLI and the `wp-cli/wp-cli` framework (via https://github.com/wp-cli/wp-cli/pull/5523) so that the `WP_CLI\Utils\http_request()` method accepts an `$insecure` option that is `false` by default and consequently that a TLS handshake failure is a hard error by default. This new default is a breaking change and ripples through to all consumers of `WP_CLI\Utils\http_request()`, including those in separate WP-CLI bundled or third-party packages. https://github.com/wp-cli/wp-cli/pull/5523 has also added an `--insecure` flag to the `cli update` command to counter this breaking change. There is no direct workaround for the default insecure behavior of `wp-cli/wp-cli` versions before 2.5.0. The workaround for dealing with the breaking change in the commands directly affected by the new secure default behavior is to add the `--insecure` flag to manually opt-in to the previous insecure behavior.

An improper certificate validation issue in Smartcard authentication in GitLab EE affecting all versions from 11.6 prior to 16.4.4, 16.5 prior to 16.5.4, and 16.6 prior to 16.6.2 allows an attacker to authenticate as another user given their public key if they use Smartcard authentication. Smartcard authentication is an experimental feature and has to be manually enabled by an administrator.

Missing SSL certificate validation in HTTPie v3.2.2 allows attackers to eavesdrop on communications between the host and server via a man-in-the-middle attack.

Codehaus XFire 1.2.6 and earlier, as used in the Amazon EC2 API Tools Java library and other products, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

em-imap 0.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.

core/imap/MCIMAPSession.cpp in Canary Mail before 3.22 has Missing SSL Certificate Validation for IMAP in STARTTLS mode.

EM-HTTP-Request 1.1.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.

The SSLVerifySignedServerKeyExchange function in libsecurity_ssl/lib/sslKeyExchange.c in the Secure Transport feature in the Data Security component in Apple iOS 6.x before 6.1.6 and 7.x before 7.0.6, Apple TV 6.x before 6.0.2, and Apple OS X 10.9.x before 10.9.2 does not check the signature in a TLS Server Key Exchange message, which allows man-in-the-middle attackers to spoof SSL servers by (1) using an arbitrary private key for the signing step or (2) omitting the signing step.

A vulnerability was found in the Hot Rod client. This security issue occurs as the Hot Rod client does not enable hostname validation when using TLS, possibly resulting in a man-in-the-middle (MITM) attack.