An issue existed in the handling of S-MIME certificates. This issue was addressed with improved validation of S-MIME certificates. This issue is fixed in macOS Mojave 10.14.4, Security Update 2019-002 High Sierra, Security Update 2019-002 Sierra. Processing a maliciously crafted mail message may lead to S/MIME signature spoofing.

vdsm and vdsclient does not validate certficate hostname from another vdsm which could facilitate a man-in-the-middle attack

There is Missing SSL Certificate Validation in the Trend Micro Enterprise Mobile Security Android Application before 9.7.1193, aka VRTS-398.

In fence-agents before 4.0.17 does not verify remote SSL certificates in the fence_cisco_ucs.py script which can potentially allow for man-in-the-middle attackers to spoof SSL servers via arbitrary SSL certificates.

Clustered Data ONTAP versions 9.0 and higher do not enforce hostname verification under certain circumstances making them susceptible to impersonation via man-in-the-middle attacks.

Google Chrome caches TLS sessions before certificate validation occurs.

The esets_daemon service in ESET Endpoint Antivirus for macOS before 6.4.168.0 and Endpoint Security for macOS before 6.4.168.0 does not properly verify X.509 certificates from the edf.eset.com SSL server, which allows man-in-the-middle attackers to spoof this server and provide crafted responses to license activation requests via a self-signed certificate. NOTE: this issue can be combined with CVE-2016-0718 to execute arbitrary code remotely as root.

The vulnerability have been reported to affect earlier versions of Helpdesk. If exploited, this improper certificate validation vulnerability could allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. QNAP has already fixed the issue in Helpdesk 3.0.3 and later.

The libwww-perl LWP::Protocol::https module 6.04 through 6.06 for Perl, when using IO::Socket::SSL as the SSL socket class, allows attackers to disable server certificate validation via the (1) HTTPS_CA_DIR or (2) HTTPS_CA_FILE environment variable.

ovirt-engine-sdk-python before 3.4.0.7 and 3.5.0.4 does not verify that the hostname of the remote endpoint matches the Common Name (CN) or subjectAltName as specified by its x.509 certificate in a TLS/SSL session. This could allow man-in-the-middle attackers to spoof remote endpoints via an arbitrary valid certificate.

Man-in-the-middle vulnerability in Micro Focus Self Service Password Reset, affecting all versions prior to 4.4.0.4. The vulnerability could exploit invalid certificate validation and may result in a man-in-the-middle attack.

OSS Http Request (Apache Cordova Plugin) 6 is affected by: Missing SSL certificate validation. The impact is: certificate spoofing. The component is: use this library when https communication. The attack vector is: certificate spoofing.

Apache Tomcat Native 1.2.0 to 1.2.16 and 1.1.23 to 1.1.34 has a flaw that does not properly check OCSP pre-produced responses, which are lists (multiple entries) of certificate statuses. Subsequently, revoked client certificates may not be properly identified, allowing for users to authenticate with revoked certificates to connections that require mutual TLS. Users not using OCSP checks are not affected by this vulnerability.

When using an OCSP responder Apache Tomcat Native 1.2.0 to 1.2.16 and 1.1.23 to 1.1.34 did not correctly handle invalid responses. This allowed for revoked client certificates to be incorrectly identified. It was therefore possible for users to authenticate with revoked certificates when using mutual TLS. Users not using OCSP checks are not affected by this vulnerability.

Mercurial before 1.6.4 fails to verify the Common Name field of SSL certificates which allows remote attackers who acquire a certificate signed by a Certificate Authority to perform a man-in-the-middle attack.

Jenkins Proxmox Plugin 0.6.0 and earlier disables SSL/TLS certificate validation globally for the Jenkins controller JVM when configured to ignore SSL/TLS issues.

OWASP Zed Attack Proxy (ZAP) through w2022-03-21 does not verify the TLS certificate chain of an HTTPS server.

Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one TLSContext is defined and at least one configuration exists that does not require client certificate authentication. The attacker must send an SNI specifying an unprotected backend and an HTTP Host header specifying a protected backend. (2.x versions are unaffected. 1.x versions are unaffected with certain configuration settings involving prune_unreachable_routes and a wildcard Host resource.)

A certificate parsing issue was addressed with improved checks. This issue is fixed in tvOS 15.5, iOS 15.5 and iPadOS 15.5, Security Update 2022-004 Catalina, watchOS 8.6, macOS Big Sur 11.6.6, macOS Monterey 12.4. A malicious app may be able to bypass signature validation.

In Mellium mellium.im/xmpp through 0.21.0, an attacker capable of spoofing DNS TXT records can redirect a WebSocket connection request to a server under their control without causing TLS certificate verification to fail. This occurs because the wrong host name is selected during this verification.

In wolfSSL before 5.2.0, certificate validation may be bypassed during attempted authentication by a TLS 1.3 client to a TLS 1.3 server. This occurs when the sig_algo field differs between the certificate_verify message and the certificate message.

The function `OCSP_basic_verify` verifies the signer certificate on an OCSP response. In the case where the (non-default) flag OCSP_NOCHECKS is used then the response will be positive (meaning a successful verification) even in the case where the response signing certificate fails to verify. It is anticipated that most users of `OCSP_basic_verify` will not use the OCSP_NOCHECKS flag. In this case the `OCSP_basic_verify` function will return a negative value (indicating a fatal error) in the case of a certificate verification failure. The normal expected return value in this case would be 0. This issue also impacts the command line OpenSSL "ocsp" application. When verifying an ocsp response with the "-no_cert_checks" option the command line application will report that the verification is successful even though it has in fact failed. In this case the incorrect successful response will also be accompanied by error messages showing the failure and contradicting the apparently successful result. Fixed in OpenSSL 3.0.3 (Affected 3.0.0,3.0.1,3.0.2).

An Improper Certificate Validation on UniFi OS devices, with Identity Enterprise configured, could allow a malicious actor to execute a man-in-the-middle (MitM) attack during application update.

An issue was discovered in certain Apple products. iOS before 11.2.5 is affected. macOS before 10.13.3 is affected. tvOS before 11.2.5 is affected. watchOS before 4.2.2 is affected. The issue involves the "Security" component. It allows remote attackers to spoof certificate validation via crafted name constraints.