The (1) CertGetCertificateChain, (2) CertVerifyCertificateChainPolicy, and (3) WinVerifyTrust APIs within the CryptoAPI for Microsoft products including Microsoft Windows 98 through XP, Office for Mac, Internet Explorer for Mac, and Outlook Express for Mac, do not properly verify the Basic Constraints of intermediate CA-signed X.509 certificates, which allows remote attackers to spoof the certificates of trusted sites via a man-in-the-middle attack for SSL sessions, as originally reported for Internet Explorer and IIS.

Open Build Service before version 0.165.4 diddn't validate TLS certificates for HTTPS connections with the osc client binary

NetApp Plug-in for Symantec NetBackup prior to version 2.0.1 makes use of a non-unique server certificate, making it vulnerable to impersonation.

Improper validation of the cloud certificate chain in Mobile Connect allows man-in-the-middle attack to impersonate the legitimate Command Centre Server. This issue affects: Gallagher Command Centre Mobile Connect for Android 15 versions prior to 15.04.040; version 14 and prior versions.

The TLS protocol 1.2 and earlier supports the rsa_fixed_dh, dss_fixed_dh, rsa_fixed_ecdh, and ecdsa_fixed_ecdh values for ClientCertificateType but does not directly document the ability to compute the master secret in certain situations with a client secret key and server public key but not a server secret key, which makes it easier for man-in-the-middle attackers to spoof TLS servers by leveraging knowledge of the secret key for an arbitrary installed client X.509 certificate, aka the "Key Compromise Impersonation (KCI)" issue.

packages/wekan-ldap/server/ldap.js in Wekan before 4.87 can process connections even though they are not authorized by the Certification Authority trust store,

DoTls13CertificateVerify in tls13.c in wolfSSL before 4.7.0 does not cease processing for certain anomalous peer behavior (sending an ED22519, ED448, ECC, or RSA signature without the corresponding certificate). The client side is affected because man-in-the-middle attackers can impersonate TLS 1.3 servers.

An issue was discovered in Couchbase Sync Gateway 3.x before 3.0.2. Admin credentials are not verified when using X.509 client-certificate authentication from Sync Gateway to Couchbase Server. When Sync Gateway is configured to authenticate with Couchbase Server using X.509 client certificates, the admin credentials provided to the Admin REST API are ignored, resulting in privilege escalation for unauthenticated users. The Public REST API is not impacted by this issue. A workaround is to replace X.509 certificate based authentication with Username and Password authentication inside the bootstrap configuration.

A spoofing vulnerability exists for the Azure IoT Device Provisioning for the C SDK library using the HTTP protocol on Windows platform, aka "Azure IoT SDK Spoofing Vulnerability." This affects C SDK.

A spoofing vulnerability exists when the Azure IoT Device Provisioning AMQP Transport library improperly validates certificates over the AMQP protocol, aka "Azure IoT SDK Spoofing Vulnerability." This affects C# SDK, C SDK, Java SDK.

VOBOT CLOCK before 0.99.30 devices do not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information, and consequently execute arbitrary code, via a crafted certificate, as demonstrated by leveraging a hardcoded --no-check-certificate Wget option.

pulp-consumer-client 2.4.0 through 2.6.3 does not check the server's TLS certificate signatures when retrieving the server's public key upon registration.

The TLS stack in Mono before 3.12.1 allows man-in-the-middle attackers to conduct message skipping attacks and consequently impersonate clients by leveraging missing handshake state validation, aka a "SMACK SKIP-TLS" issue.

Hammer CLI, a CLI utility for Foreman, before version 0.10.0, did not explicitly set the verify_ssl flag for apipie-bindings that disable it by default. As a result the server certificates are not checked and connections are prone to man-in-the-middle attacks.

The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."