The mechanism which performs certificate validation was discovered to have a flaw that resulted in certificates signed by an internal certificate authority to not be properly validated. This issue only affects clients that are configured to utilize Tenable.sc as the vulnerability data source.

Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL certificate verification when using the "Register with a Provider" flow.

IBM Security Secret Server prior to 10.9 could allow an attacker to bypass SSL security due to improper certificate validation. IBM X-Force ID: 178180.

An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).

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.

A flaw in Mozilla's embedded certificate code might allow web sites to install root certificates on devices without user approval.

In mainwindow.cpp in Shotcut before 20.09.13, the upgrade check misuses TLS because of setPeerVerifyMode(QSslSocket::VerifyNone). A man-in-the-middle attacker could offer a spoofed download resource.

In voloko twitter-stream 0.1.10, missing TLS hostname validation allows an attacker to perform a man-in-the-middle attack against users of the library (because eventmachine is misused).

TweetStream 2.6.1 uses the library eventmachine in an insecure way that does not have TLS hostname validation. This allows an attacker to perform a man-in-the-middle attack.

An issue was discovered on ASUS RT-AC1900P routers before 3.0.0.4.385_20253. The router accepts an arbitrary server certificate for a firmware update. The culprit is the --no-check-certificate option passed to wget tool used to download firmware update files.

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.

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.

PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, on GnuTLS builds, the SIP TLS transport (sip_transport_tls) can accept connections with invalid or untrusted certificates even when the application explicitly enables certificate verification via verify_server = PJ_TRUE or verify_client = PJ_TRUE. This issue has been patched in version 2.17.

The Chase mobile banking application for Android 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, related to overriding the default X509TrustManager. NOTE: this vulnerability was fixed in the summer of 2012, but the version number was not changed or is not known.

The Apache Bookkeeper Java Client (before 4.14.6 and also 4.15.0) does not close the connection to the bookkeeper server when TLS hostname verification fails. This leaves the bookkeeper client vulnerable to a man in the middle attack. The problem affects BookKeeper client prior to versions 4.14.6 and 4.15.1.

HTTPSConnections in OpenStack Keystone 2013, OpenStack Compute 2013.1, and possibly other OpenStack components, fail to validate server-side SSL certificates.

Botan is a C++ cryptography library. Prior to version 3.11.0, during processing of an X.509 certificate path using name constraints which restrict the set of allowable DNS names, if no subject alternative name is defined in the end-entity certificate Botan would check that the CN was allowed by the DNS name constraints, even though this check is technically not required by RFC 5280. However this check failed to account for the possibility of a mixed-case CN. Thus a certificate with CN=Sub.EVIL.COM and no subject alternative name would bypasses an excludedSubtrees constraint for evil.com because the comparison is case-sensitive. This issue has been patched in version 3.11.0.

A missing secure communication definition and an incomplete TLS validation in the upgrade service in B&R Automation Studio versions 4.0.x, 4.1.x, 4.2.x, < 4.3.11SP, < 4.4.9SP, < 4.5.5SP, < 4.6.4 and < 4.7.2 enable unauthenticated users to perform MITM attacks via the B&R upgrade server.

Lynx does not verify that the server's certificate is signed by a trusted certification authority, which allows man-in-the-middle attackers to spoof SSL servers via a crafted certificate, related to improper use of a certain GnuTLS function.

vdsm: certificate generation upon node creation allowing vdsm to start and serve requests from anyone who has a matching key (and certificate)

daneren2005 DSub for Subsonic (Android client) version 5.4.1 contains a CWE-295: Improper Certificate Validation vulnerability in HTTPS Client that can result in Any non-CA signed server certificate, including self signed and expired, are accepted by the client. This attack appear to be exploitable via The victim connects to a server that's MITM/Proxied by an attacker.

Hostname verification in Apache ZooKeeper ZKTrustManager falls back to reverse DNS (PTR) when IP SAN validation fails, allowing attackers who control or spoof PTR records to impersonate ZooKeeper servers or clients with a valid certificate for the PTR name. It's important to note that attacker must present a certificate which is trusted by ZKTrustManager which makes the attack vector harder to exploit. Users are recommended to upgrade to version 3.8.6 or 3.9.5, which fixes this issue by introducing a new configuration option to disable reverse DNS lookup in client and quorum protocols.

Apache Libcloud before 0.11.1 uses an incorrect regular expression during verification of whether 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 a crafted certificate.

The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the <Ssl> element. Although the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value. A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met: * An SMTP, Socket, or Syslog appender is in use. * TLS is configured via a nested <Ssl> element. * The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured. This issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName attribute that was not subject to this bug and verifies host names by default. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.

Cisco IronPort Web Security Appliance does not check for certificate revocation which could lead to MITM attacks

PostgreSQL 8.4.x before 8.4.11, 9.0.x before 9.0.7, and 9.1.x before 9.1.3 truncates the common name to only 32 characters when verifying SSL certificates, which allows remote attackers to spoof connections when the host name is exactly 32 characters.

Amazon SageMaker Python SDK before v3.1.1 or v2.256.0 disables TLS certificate verification for HTTPS connections made by the service when a Triton Python model is imported, incorrectly allowing for requests with invalid and self-signed certificates to succeed.

An exploitable vulnerability exists in the filtering functionality of Circle with Disney. SSL certificates for specific domain names can cause the Bluecoat library to accept a different certificate than intended. An attacker can host an HTTPS server with this certificate to trigger this vulnerability.

IBM Concert 1.0.0 and 1.0.1 vulnerable to attacks that rely on the use of cookies without the SameSite attribute.

It was discovered that rpm-ostree and rpm-ostree-client before 2017.3 fail to properly check GPG signatures on packages when doing layering. Packages with unsigned or badly signed content could fail to be rejected as expected. This issue is partially mitigated on RHEL Atomic Host, where certificate pinning is used by default.

An improper certificate validation vulnerability exists in curl <v8.1.0 in the way it supports matching of wildcard patterns when listed as "Subject Alternative Name" in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS library. This private wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before used for certificate checks. Puny coded names always start with `xn--` and should not be allowed to pattern match, but the wildcard check in curl could still check for `x*`, which would match even though the IDN name most likely contained nothing even resembling an `x`.

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.

An improper certificate validation vulnerability in the Prisma® Access Agent for iOS enables an attacker to perform a man-in-the-middle (MitM) attack to intercept VPN traffic. The Prisma Access Agent on Windows, macOS, Linux, Android and ChromeOS are not affected.

offlineimap before 6.3.2 does not check for SSL server certificate validation when "ssl = yes" option is specified which can allow man-in-the-middle attacks.

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.

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.

Prior to v 7.6, the Install Norton Security (INS) product can be susceptible to a certificate spoofing vulnerability, which is a type of attack whereby a maliciously procured certificate binds the public key of an attacker to the domain name of the target.

A Improper Certificate Validation vulnerability in susestudio-common of SUSE Studio onsite allows remote attackers to MITM connections to the repositories, which allows the modification of packages received over these connections. This issue affects: SUSE Studio onsite susestudio-common version 1.3.17-56.6.3 and prior versions.

Mozilla Network Security Services (NSS) before 3.12.3, Firefox before 3.0.13, Thunderbird before 2.0.0.23, and SeaMonkey before 1.1.18 do not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority. NOTE: this was originally reported for Firefox before 3.5.

nheko is a desktop client for the Matrix communication application. All versions below 0.10.2 are vulnerable homeservers inserting malicious secrets, which could lead to man-in-the-middle attacks. Users can upgrade to version 0.10.2 to protect against this issue. As a workaround, one may apply the patch manually, avoid doing verifications of one's own devices, and/or avoid pressing the request button in the settings menu.

IBM Security Guardium 10.0, 10.0.1, 10.1, 10.1.2, 10.1.3, 10.1.4, and 10.5 does not validate, or incorrectly validates, a certificate. This weakness might allow an attacker to spoof a trusted entity by using a man-in-the-middle (MITM) techniques. IBM X-Force ID: 124740.

Jenkins 2.73.1 and earlier, 2.83 and earlier bundled a version of the commons-httpclient library with the vulnerability CVE-2012-6153 that incorrectly verified SSL certificates, making it susceptible to man-in-the-middle attacks. This library is widely used as a transitive dependency in Jenkins plugins. The fix for CVE-2012-6153 was backported to the version of commons-httpclient that is bundled in core and made available to plugins.

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.

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.

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

Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

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.