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.

Multiple MFPs provided by Brother Industries, Ltd. does not properly validate server certificates, which may allow a man-in-the-middle attacker to replace the set of root certificates used by the product with a set of arbitrary certificates.

A vulnerability was identified in Tomofun Furbo 360 and Furbo Mini. Affected by this issue is the function upload_file_to_s3 of the file collect_logs.sh of the component HTTP Traffic Handler. The manipulation leads to improper certificate validation. The attack may be initiated remotely. The attack is considered to have high complexity. The exploitation is known to be difficult. The firmware versions determined to be affected are Furbo 360 up to FB0035_FW_036 and Furbo Mini up to MC0020_FW_074. The vendor was contacted early about this disclosure but did not respond in any way.

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.

JRuby-OpenSSL is an add-on gem for JRuby that emulates the Ruby OpenSSL native library. Starting in JRuby-OpenSSL version 0.12.1 and prior to version 0.15.4 (corresponding to JRuby versions starting in 9.3.4.0 prior to 9.4.12.1 and 10.0.0.0 prior to 10.0.0.1), when verifying SSL certificates, JRuby-OpenSSL does not verify that the hostname presented in the certificate matches the one the user tries to connect to. This means a man-in-the-middle could just present any valid cert for a completely different domain they own, and JRuby would accept the cert. Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely. JRuby-OpenSSL version 0.15.4 contains a fix for the issue. This fix is included in JRuby versions 10.0.0.1 and 9.4.12.1.

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.

A vulnerability was found in HybridAuth up to 3.12.2. This issue affects some unknown processing of the file src/HttpClient/Curl.php of the component SSL Handler. The manipulation of the argument curlOptions results in improper certificate validation. The attack can be launched remotely. This attack is characterized by high complexity. The exploitability is assessed as difficult. The project was informed of the problem early through an issue report but has not responded yet.

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.

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.

Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows forged OCSP responses signed with an expired responder certificate to be accepted as valid. OCSP response verification in pubkey_ocsp:verify_response/5 and pubkey_ocsp:is_authorized_responder/3 in lib/public_key/src/pubkey_ocsp.erl does not check the validity period (notBefore/notAfter) of the OCSP responder certificate. An attacker who has obtained the private key of an expired CA-designated OCSP responder certificate can forge OCSP responses that Erlang/OTP accepts as valid. This affects TLS clients using OCSP stapling via the ssl application: a malicious or compromised server can present a revoked TLS certificate together with a forged OCSP response signed by an expired responder key, and the client will accept the revoked certificate as valid. It also affects applications calling public_key:pkix_ocsp_validate/5 directly, where the impact depends on the use case — server-side client certificate validation using this API may allow authentication bypass with a revoked client certificate. This issue affects OTP from OTP 27.0 before OTP 27.3.4.12, 28.5.0.1, and 29.0.1 corresponding to public_key from 1.16 before 1.17.1.3, 1.20.3.1, and 1.21.1.

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.

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

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.

Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.

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.

The DDNS function uses an insecure HTTP connection or fails to validate the SSL/TLS certificate when querying an external server for the device's WAN IP address. An unauthenticated remote attacker can perform a Man-in-the-Middle (MitM) attack to spoof the response, leading the device to update its DDNS record with an incorrect IP address. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.ROF1 as well as from ADM 5.0.0 through ADM 5.1.1.RCI1.

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.

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.

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.

A vulnerability classified as critical has been found in Comodo Internet Security Premium 12.3.4.8162. This affects an unknown part of the component Update Handler. The manipulation leads to improper certificate validation. It is possible to initiate the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The vendor was contacted early about this disclosure but did not respond in any way.

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.

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.

A vulnerability in Samsung Exynos Modem 5300 allows a Man-in-the-Middle (MITM) attacker to downgrade the security mode of packets going to the victim, enabling the attacker to send messages to the victim in plaintext.

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.

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.

Tokyo Star bank App for Android before 1.4 and Tokyo Star bank App for iOS before 1.4 do not validate SSL certificates.

IBM BigFix Remote Control before Interim Fix pack 9.1.2-TIV-IBRC912-IF0001 improperly allows self-signed certificates, which might allow remote attackers to conduct spoofing attacks via unspecified vectors. IBM X-Force ID: 105200.

The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.

Restkit allows man-in-the-middle attackers to spoof TLS servers by leveraging use of the ssl.wrap_socket function in Python with the default CERT_NONE value for the cert_reqs argument.

Oracle MySQL before 5.7.3, Oracle MySQL Connector/C (aka libmysqlclient) before 6.1.3, and MariaDB before 5.5.44 use the --ssl option to mean that SSL is optional, which allows man-in-the-middle attackers to spoof servers via a cleartext-downgrade attack, aka a "BACKRONYM" attack.

Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS by default. In case of error it falls back to a non-TLS URL http://irclogs.nim-lang.org/packages.json. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.

A certificate validation issue was addressed. This issue is fixed in iOS 14.5 and iPadOS 14.5. An attacker in a privileged network position may be able to alter network traffic.