Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.6.1, Traefik skips the router transport layer security (TLS) configuration when the host header is a fully qualified domain name (FQDN). For a request, the TLS configuration choice can be different than the router choice, which implies the use of a wrong TLS configuration. When sending a request using FQDN handled by a router configured with a dedicated TLS configuration, the TLS configuration falls back to the default configuration that might not correspond to the configured one. If the CNAME flattening is enabled, the selected TLS configuration is the SNI one and the routing uses the CNAME value, so this can skip the expected TLS configuration. Version 2.6.1 contains a patch for this issue. As a workaround, one may add the FDQN to the host rule. However, there is no workaround if the CNAME flattening is enabled.

configurationwatcher.go in Traefik 2.x before 2.1.4 and TraefikEE 2.0.0 mishandles the purging of certificate contents from providers before logging.

Traefik 2.x, in certain configurations, allows HTTPS sessions to proceed without mutual TLS verification in a situation where ERR_BAD_SSL_CLIENT_AUTH_CERT should have occurred.

Traefik is an open source HTTP reverse proxy and load balancer. In affected versions there is a potential vulnerability in Traefik managing TLS connections. A router configured with a not well-formatted TLSOption is exposed with an empty TLSOption. For instance, a route secured using an mTLS connection set with a wrong CA file is exposed without verifying the client certificates. Users are advised to upgrade to version 2.9.6. Users unable to upgrade should check their logs to detect the error messages and fix your TLS options.

A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.

An improper certificate validation vulnerability [CWE-295] in FortiClientWindows 6.4 all versions, 7.0.0 through 7.0.7, FortiClientMac 6.4 all versions, 7.0 all versions, 7.2.0 through 7.2.4, FortiClientLinux 6.4 all versions, 7.0 all versions, 7.2.0 through 7.2.4, FortiClientAndroid 6.4 all versions, 7.0 all versions, 7.2.0 and FortiClientiOS 5.6 all versions, 6.0.0 through 6.0.1, 7.0.0 through 7.0.6 SAML SSO feature may allow an unauthenticated attacker to man-in-the-middle the communication between the FortiClient and  both the service provider and the identity provider.

It was discovered that when acting as TLS clients, Beats, Elastic Agent, APM Server, and Fleet Server did not verify whether the server certificate is valid for the target IP address; however, certificate signature validation is still performed. More specifically, when the client is configured to connect to an IP address (instead of a hostname) it does not validate the server certificate's IP SAN values against that IP address and certificate validation fails, and therefore the connection is not blocked as expected.

Cyberduck before 4.4.4 on Windows does not properly validate X.509 certificate chains, which allows man-in-the-middle attackers to spoof FTP-SSL servers via a certificate issued by an arbitrary root Certification Authority.

Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server could present a self-signed certificate, complete the STARTTLS upgrade, and capture the SMTP credentials sent during the subsequent `login()` call. Users are advised to upgrade to the `apache-airflow-providers-smtp` version that contains the fix.

IBM Concert Software 1.0.0 through 1.1.0 could allow a remote attacker to perform unauthorized actions using man in the middle techniques due to improper certificate validation.

Improper certificate validation in the identity provider connection components in Amazon Athena ODBC driver before 2.1.0.0 might allow a man-in-the-middle threat actor to intercept authentication credentials due to insufficient default transport security when connecting to identity providers. This only applies to connections with external identity providers and does not apply to connections with Athena. To remediate this issue, users should upgrade to version 2.1.0.0.

Samsung Internet for Galaxy Watch version 5.0.9, available up until Samsung Galaxy Watch 3, does not properly validate TLS certificates, allowing for an attacker to impersonate any and all websites visited by the user. This is a critical misconfiguration in the way the browser validates the identity of the server. It negates the use of HTTPS as a secure channel, allowing for Man-in-the-Middle attacks, stealing sensitive information or modifying incoming and outgoing traffic. NOTE: This vulnerability is in an end-of-life product that is no longer maintained by the vendor.

IBM MQ Operator LTS 2.0.0 through 2.0.29, MQ Operator CD 3.0.0, 3.0.1, 3.1.0 through 3.1.3, 3.3.0, 3.4.0, 3.4.1, 3.5.0, 3.5.1, 3.6.0, and MQ Operator SC2 3.2.0 through 3.2.13 Internet Pass-Thru could allow a malicious user to obtain sensitive information from another TLS session connection by the proxy to the same hostname and port due to improper certificate validation.

Mod_gnutls is a TLS module for Apache HTTPD based on GnuTLS. Prior to version 0.13.0, code for client certificate verification did not check the key purpose as set in the Extended Key Usage extension. An attacker with access to the private key for a valid certificate issued by a CA trusted for TLS client authentication but designated for a different purpose could have used that certificate to improperly access resources requiring TLS client authentication. Server configurations that do not use client certificates (`GnuTLSClientVerify ignore`, the default) are not affected. The problem has been fixed in version 0.13.0 by rewriting certificate verification to use `gnutls_certificate_verify_peers()`, and requiring key purpose id-kp-clientAuth (also known as `tls_www_client` in GnuTLS) by default if the Extended Key Usage extension is present. The new `GnuTLSClientKeyPurpose` option allows overriding the expected key purpose if needed (please see the manual for details). Behavior for certificates without an Extended Key Usage extension is unchanged. If dedicated (sub-)CAs are used for issuing TLS client certificates only (not for any other purposes) the issue has no practical impact.

OpenVPN Connect versions before 3.4.0.4506 (macOS) and OpenVPN Connect before 3.4.0.3100 (Windows) allows man-in-the-middle attackers to intercept configuration profile download requests which contains the users credentials

In SaltStack Salt before 3002.5, authentication to VMware vcenter, vsphere, and esxi servers (in the vmware.py files) does not always validate the SSL/TLS certificate.

The DDNS update function in ADM fails to properly validate the hostname of the DDNS server's TLS/SSL certificate. Although the connection uses HTTPS, an improper validated TLS/SSL certificates allows a remote attacker can intercept the communication to perform a Man-in-the-Middle (MitM) attack, which may obtain the sensitive information of DDNS updating process, including the user's account email, MD5 hashed password, and device serial number.This issue affects ADM: from 4.1.0 through 4.3.3.ROF1, from 5.0.0 through 5.1.1.RCI1.

A vulnerability in certificate validation processing of Cisco Catalyst SD-WAN Manager, formerly Cisco SD-WAN vManage, could allow an unauthenticated, remote attacker to gain access to sensitive information. This vulnerability is due to improper validation of certificates that are used by the Smart Licensing feature. An attacker with a privileged network position could exploit this vulnerability by intercepting traffic that is sent over the Internet. A successful exploit could allow the attacker to gain access to sensitive information, including credentials used by the device to connect to Cisco cloud services.

GNOME Geary before 3.36.3 mishandles pinned TLS certificate verification for IMAP and SMTP services using invalid TLS certificates (e.g., self-signed certificates) when the client system is not configured to use a system-provided PKCS#11 store. This allows a meddler in the middle to present a different invalid certificate to intercept incoming and outgoing mail.

TLS hostname verification cannot be enabled in the Pulsar Broker's Java Client, the Pulsar Broker's Java Admin Client, the Pulsar WebSocket Proxy's Java Client, and the Pulsar Proxy's Admin Client leaving intra-cluster connections and geo-replication connections vulnerable to man in the middle attacks, which could leak credentials, configuration data, message data, and any other data sent by these clients. The vulnerability is for both the pulsar+ssl protocol and HTTPS. An attacker can only take advantage of this vulnerability by taking control of a machine 'between' the client and the server. The attacker must then actively manipulate traffic to perform the attack by providing the client with a cryptographically valid certificate for an unrelated host. This issue affects Apache Pulsar Broker, Proxy, and WebSocket Proxy versions 2.7.0 to 2.7.4; 2.8.0 to 2.8.3; 2.9.0 to 2.9.2; 2.10.0; 2.6.4 and earlier.

The API communication component fails to validate the SSL/TLS certificate when sending HTTPS requests to the server. An improper certificates validation vulnerability allows an unauthenticated remote attacker can perform a Man-in-the-Middle (MitM) attack to intercept the cleartext communication, potentially leading to the exposure of sensitive user information, including account emails, MD5 hashed passwords, and device serial numbers. 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.

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.

Apache Pulsar Brokers and Proxies create an internal Pulsar Admin Client that does not verify peer TLS certificates, even when tlsAllowInsecureConnection is disabled via configuration. The Pulsar Admin Client's intra-cluster and geo-replication HTTPS connections are vulnerable to man in the middle attacks, which could leak authentication data, configuration data, and any other data sent by these clients. An attacker can only take advantage of this vulnerability by taking control of a machine 'between' the client and the server. The attacker must then actively manipulate traffic to perform the attack. This issue affects Apache Pulsar Broker and Proxy versions 2.7.0 to 2.7.4; 2.8.0 to 2.8.3; 2.9.0 to 2.9.2; 2.10.0; 2.6.4 and earlier.

Apache Airflow SMTP Provider before 1.3.0, Apache Airflow IMAP Provider before 3.3.0, and Apache Airflow before 2.7.0 are affected by the Validation of OpenSSL Certificate vulnerability. The default SSL context with SSL library did not check a server's X.509 certificate.  Instead, the code accepted any certificate, which could result in the disclosure of mail server credentials or mail contents when the client connects to an attacker in a MITM position. Users are strongly advised to upgrade to Apache Airflow version 2.7.0 or newer, Apache Airflow IMAP Provider version 3.3.0 or newer, and Apache Airflow SMTP Provider version 1.3.0 or newer to mitigate the risk associated with this vulnerability

The Sophos Secure Email application through 3.9.4 for Android has Missing SSL Certificate Validation.

An issue was discovered in ssl.c in Axel before 2.17.8. The TLS implementation lacks hostname verification.

An issue was discovered in Django 2.2 before 2.2.13 and 3.0 before 3.0.7. In cases where a memcached backend does not perform key validation, passing malformed cache keys could result in a key collision, and potential data leakage.

An issue was discovered in Pidgin before 2.14.9. A remote attacker who can spoof DNS responses can redirect a client connection to a malicious server. The client will perform TLS certificate verification of the malicious domain name instead of the original XMPP service domain, allowing the attacker to take over control over the XMPP connection and to obtain user credentials and all communication content. This is similar to CVE-2022-24968.

When the user set the Notification's sender to send emails to the SMTP server via msmtp, an improper validated TLS/SSL certificates allows an attacker who can intercept network traffic between the SMTP client and server to execute a man-in-the-middle (MITM) attack, which may obtain the sensitive information of the SMTP. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RKD2 as well as from ADM 5.0.0 through ADM 5.1.0.RN42.

In MailStore Outlook Add-in (and Email Archive Outlook Add-in) through 12.1.2, the login process does not validate the validity of the certificate presented by the server.

A CWE-295: Improper Certificate Validation vulnerability exists that could allow a Man-in-theMiddle attack when communications between the client and Geo SCADA web server are intercepted. Affected Product: ClearSCADA (All Versions), EcoStruxure Geo SCADA Expert 2019 (All Versions), EcoStruxure Geo SCADA Expert 2020 (All Versions)

An improper certificate validation vulnerability [CWE-295] in FortiADC 7.4.0, 7.2 all versions, 7.1 all versions, 7.0 all versions may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the device and public SDN connectors.

Multiple vulnerabilities in the API and in the web-based management interface of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow a remote attacker to overwrite arbitrary files or conduct null byte poisoning attacks on an affected device. Note: Cisco Expressway Series refers to the Expressway Control (Expressway-C) device and the Expressway Edge (Expressway-E) device. For more information about these vulnerabilities, see the Details section of this advisory.

In A-GPS, there is a possible man in the middle attack due to improper certificate validation. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS06461919; Issue ID: ALPS06461919.

IBM QRadar SIEM 7.2.8 WinCollect could allow an attacker to obtain sensitive information by spoofing a trusted entity using man in the middle techniques due to not validating or incorrectly validating a certificate. IBM X-Force ID: 160072.

Sensitive information disclosure vulnerability resulting from a lack of certificate validation during the File-Based Backup and Restore operations of VMware vCenter Server Appliance (6.7 before 6.7u3a and 6.5 before 6.5u3d) may allow a malicious actor to intercept sensitive data in transit over FTPS and HTTPS. A malicious actor with man-in-the-middle positioning between vCenter Server Appliance and a backup target may be able to intercept sensitive data in transit during File-Based Backup and Restore operations.

Sensitive information disclosure vulnerability resulting from a lack of certificate validation during the File-Based Backup and Restore operations of VMware vCenter Server Appliance (6.7 before 6.7u3a and 6.5 before 6.5u3d) may allow a malicious actor to intercept sensitive data in transit over SCP. A malicious actor with man-in-the-middle positioning between vCenter Server Appliance and a backup target may be able to intercept sensitive data in transit during File-Based Backup and Restore operations.

Dell Unity prior to 5.3 contains a 'man in the middle' vulnerability in the vmadapter component. If a customer has a certificate signed by a third-party public Certificate Authority, the vCenter CA could be spoofed by an attacker who can obtain a CA-signed certificate.

Missing SSL Certificate Validation in the Nutfind.com application through 3.9.12 for Android allows a man-in-the-middle attacker to sniff and manipulate all API requests, including login credentials and location data.

Velneo vClient on its 28.1.3 version, does not correctly check the certificate of authenticity by default. This could allow an attacker that has access to the network to perform a MITM attack in order to obtain the user´s credentials.

IBM WebSphere Application Server 8.5 and 9.0 could allow an attacker with access to the network to conduct spoofing attacks. An attacker could exploit this vulnerability using a certificate issued by a trusted authority to obtain sensitive information. IBM X-Force ID: 274714.

An information disclosure vulnerability exists in the way Rome SDK handles server SSL/TLS certificate validation, aka 'Rome SDK Information Disclosure Vulnerability'.

Adobe Experience Manager version 6.5.9.0 (and earlier) is affected by a improper certificate validation vulnerability in the cold storage component. If an attacker can achieve a man in the middle when the cold server establishes a new certificate, they would be able to harvest sensitive information.

In GNOME libgfbgraph through 0.2.4, gfbgraph-photo.c does not enable TLS certificate verification on the SoupSessionSync objects it creates, leaving users vulnerable to network MITM attacks. NOTE: this is similar to CVE-2016-20011.

In GNOME libzapojit through 0.0.3, zpj-skydrive.c does not enable TLS certificate verification on the SoupSessionSync objects it creates, leaving users vulnerable to network MITM attacks. NOTE: this is similar to CVE-2016-20011.

In GNOME grilo though 0.3.13, grl-net-wc.c does not enable TLS certificate verification on the SoupSessionAsync objects it creates, leaving users vulnerable to network MITM attacks. NOTE: this is similar to CVE-2016-20011.

In GNOME libgda through 6.0.0, gda-web-provider.c does not enable TLS certificate verification on the SoupSessionSync objects it creates, leaving users vulnerable to network MITM attacks. NOTE: this is similar to CVE-2016-20011.

In GNOME evolution-rss through 0.3.96, network-soup.c does not enable TLS certificate verification on the SoupSessionSync objects it creates, leaving users vulnerable to network MITM attacks. NOTE: this is similar to CVE-2016-20011.

An issue in CP Plus CP-VNR-3104 B3223P22C02424 allows attackers to obtain the EC private key and access sensitive data or execute a man-in-the-middle attack.

An issue in CP Plus CP-VNR-3104 B3223P22C02424 allows attackers to obtain the second RSA private key and access sensitive data or execute a man-in-the-middle attack.