A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates.An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source, aka 'Windows CryptoAPI Spoofing Vulnerability'.

HttpUtils#getURLConnection method disables explicitly hostname verification for HTTPS connections making clients vulnerable to man-in-the-middle attacks. Calcite uses internally this method to connect with Druid and Splunk so information leakage may happen when using the respective Calcite adapters. The method itself is in a utility class so people may use it to create vulnerable HTTPS connections for other applications. From Apache Calcite 1.26 onwards, the hostname verification will be performed using the default JVM truststore.

Ptarmigan before 0.2.3 lacks API token validation, e.g., an "if (token === apiToken) {return true;} return false;" code block.

Backblaze for Windows before 7.0.1.433 and Backblaze for macOS before 7.0.1.434 suffer from improper certificate validation in `bztransmit` helper due to hardcoded whitelist of strings in URLs where validation is disabled leading to possible remote code execution via client update functionality.

iSM client versions from V5.1 prior to V12.1 running on NEC Storage Manager or NEC Storage Manager Express does not verify a server certificate properly, which allows a man-in-the-middle attacker to eavesdrop on an encrypted communication or alter the communication via a crafted certificate.

Icinga 2 v2.8.0 through v2.11.7 and v2.12.2 has an issue where revoked certificates due for renewal will automatically be renewed, ignoring the CRL. This issue is fixed in Icinga 2 v2.11.8 and v2.12.3.

curl 7.41.0 through 7.73.0 is vulnerable to an improper check for certificate revocation due to insufficient verification of the OCSP response.

Tesla Model X vehicles before 2020-11-23 do not perform certificate validation during an attempt to pair a new key fob with the body control module (BCM). This allows an attacker (who is inside a vehicle, or is otherwise able to send data over the CAN bus) to start and drive the vehicle with a spoofed key fob.

An issue exists in PrimeKey EJBCA before 7.4.3 when enrolling with EST while proxied through an RA over the Peers protocol. As a part of EJBCA's domain security model, the peer connector allows the restriction of client certificates (for the RA, not the end user) to a limited set of allowed CAs, thus restricting the accessibility of that RA to the rights it has within a specific role. While this works for other protocols such as CMP, it was found that the EJBCA enrollment over an EST implementation bypasses this check, allowing enrollment with a valid client certificate through any functioning and authenticated RA connected to the CA. NOTE: an attacker must already have a trusted client certificate and authorization to enroll against the targeted CA.

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