An improper certificate validation vulnerability exists in Jenkins Active Directory Plugin 2.10 and earlier in src/main/java/hudson/plugins/active_directory/ActiveDirectoryDomain.java, src/main/java/hudson/plugins/active_directory/ActiveDirectorySecurityRealm.java, src/main/java/hudson/plugins/active_directory/ActiveDirectoryUnixAuthenticationProvider.java that allows attackers to impersonate the Active Directory server Jenkins connects to for authentication if Jenkins is configured to use StartTLS.

An Improper Certificate Validation weakness in the SRX Series Application Identification (app-id) signature update client of Juniper Networks Junos OS allows an attacker to perform Man-in-the-Middle (MitM) attacks which may compromise the integrity and confidentiality of the device. This issue affects: Juniper Networks Junos OS 15.1X49 versions prior to 15.1X49-D120 on SRX Series devices. No other versions of Junos OS are affected.

The int_x509_param_set_hosts function in lib/libcrypto/x509/x509_vpm.c in LibreSSL 2.7.0 before 2.7.1 does not support a certain special case of a zero name length, which causes silent omission of hostname verification, and consequently allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate. NOTE: the LibreSSL documentation indicates that this special case is supported, but the BoringSSL documentation does not.

A man in the middle vulnerability exists in Jenkins Inedo BuildMaster Plugin 1.3 and earlier in BuildMasterConfiguration.java, BuildMasterConfig.java, BuildMasterApi.java that allows attackers to impersonate any service that Jenkins connects to.

A man in the middle vulnerability exists in Jenkins TraceTronic ECU-TEST Plugin 2.3 and earlier in ATXPublisher.java, ATXValidator.java that allows attackers to impersonate any service that Jenkins connects to.

A man in the middle vulnerability exists in Jenkins Inedo ProGet Plugin 0.8 and earlier in ProGetApi.java, ProGetConfig.java, ProGetConfiguration.java that allows attackers to impersonate any service that Jenkins connects to.

Trillian 5.1.0.19 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, a different vulnerability than CVE-2009-4831.

Acronis True Image prior to 2021 Update 4 for Windows, Acronis True Image prior to 2021 Update 5 for Mac, Acronis Agent prior to build 26653, Acronis Cyber Protect prior to build 27009 did not implement SSL certificate validation.

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.

Multiple vulnerabilities in Cisco Data Center Network Manager (DCNM) could allow an attacker to spoof a trusted host or construct a man-in-the-middle attack to extract sensitive information or alter certain API requests. These vulnerabilities are due to insufficient certificate validation when establishing HTTPS requests with the affected device. For more information about these vulnerabilities, see the Details section of this advisory.

In versions 3.0.0-3.5.0, 2.0.0-2.9.0, and 1.0.1, when users run the command displayed in NGINX Controller user interface (UI) to fetch the agent installer, the server TLS certificate is not verified.

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.

When linking a Nessus scanner or agent to Tenable.io or other manager, Nessus 6.x before 6.11 does not verify the manager's TLS certificate when making the initial outgoing connection. This could allow man-in-the-middle attacks.

VMware vCenter Server (6.7 before 6.7u3, 6.6 before 6.5u3k) contains a session hijack vulnerability in the vCenter Server Appliance Management Interface update function due to a lack of certificate validation. A malicious actor with network positioning between vCenter Server and an update repository may be able to perform a session hijack when the vCenter Server Appliance Management Interface is used to download vCenter updates.

A vulnerability in the SSL implementation of the Cisco Intelligent Proximity solution could allow an unauthenticated, remote attacker to view or alter information shared on Cisco Webex video devices and Cisco collaboration endpoints if the products meet the conditions described in the Vulnerable Products section. The vulnerability is due to a lack of validation of the SSL server certificate received when establishing a connection to a Cisco Webex video device or a Cisco collaboration endpoint. An attacker could exploit this vulnerability by using man in the middle (MITM) techniques to intercept the traffic between the affected client and an endpoint, and then using a forged certificate to impersonate the endpoint. Depending on the configuration of the endpoint, an exploit could allow the attacker to view presentation content shared on it, modify any content being presented by the victim, or have access to call controls. This vulnerability does not affect cloud registered collaboration endpoints.

A TLS certificate validation flaw was found in Elastic APM agent for Ruby versions before 2.9.0. When specifying a trusted server CA certificate via the 'server_ca_cert' setting, the Ruby agent would not properly verify the certificate returned by the APM server. This could result in a man in the middle style attack against the Ruby agent.