Missing validation of server certificates for out-going connections in Nextcloud Social < 0.4.0 allowed a man-in-the-middle attack.

In BIG-IP Versions 15.1.x before 15.1.6.1, 14.1.x before 14.1.5, and all versions of 13.1.x, Traffic Intelligence feeds, which use HTTPS, do not verify the remote endpoint identity, allowing for potential data poisoning. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Usage of specific command line parameter in MongoDB Tools which was originally intended to just skip hostname checks, may result in MongoDB skipping all certificate validation. This may result in accepting invalid certificates.This issue affects: MongoDB Inc. MongoDB Database Tools 3.6 versions later than 3.6.5; 3.6 versions prior to 3.6.21; 4.0 versions prior to 4.0.21; 4.2 versions prior to 4.2.11; 100 versions prior to 100.2.0. MongoDB Inc. Mongomirror 0 versions later than 0.6.0.

When AdaCore Ada Web Server 25.0.0 is linked with GnuTLS, the default behaviour of AWS.Client is vulnerable to a man-in-the-middle attack because of lack of verification of an HTTPS server's certificate (unless the using program specifies a TLS configuration).

Improper handling and storage of certificates in CP Plus CP-VNR-3104 B3223P22C02424 allow attackers to decrypt communications or execute a man-in-the-middle attacks.

TLS session reuse can lead to host certificate verification bypass in node version < 12.18.0 and < 14.4.0.

Starting with diego-release 2.55.0 and up to 2.69.0, and starting with CF Deployment 17.1 and up to 23.2.0, apps are accessible via another port on diego cells, allowing application ingress without a client certificate. If mTLS route integrity is enabled AND unproxied ports are turned off, then an attacker could connect to an application that should be only reachable via mTLS, without presenting a client certificate.

Improper certificate validation for certain connections in the Bosch Smart Home System App for iOS prior to version 9.17.1 potentially allows to intercept video contents by performing a man-in-the-middle attack.

fs2 is a compositional, streaming I/O library for Scala. When establishing a server-mode `TLSSocket` using `fs2-io` on Node.js, the parameter `requestCert = true` is ignored, peer certificate verification is skipped, and the connection proceeds. The vulnerability is limited to: 1. `fs2-io` running on Node.js. The JVM TLS implementation is completely independent. 2. `TLSSocket`s in server-mode. Client-mode `TLSSocket`s are implemented via a different API. 3. mTLS as enabled via `requestCert = true` in `TLSParameters`. The default setting is `false` for server-mode `TLSSocket`s. It was introduced with the initial Node.js implementation of fs2-io in 3.1.0. A patch is released in v3.2.11. The requestCert = true parameter is respected and the peer certificate is verified. If verification fails, a SSLException is raised. If using an unpatched version on Node.js, do not use a server-mode TLSSocket with requestCert = true to establish a mTLS connection.

The functions to fetch e-mail via POP3 or IMAP as well as sending e-mail via SMTP use OpenSSL for static SSL or TLS based communication. As the SSL_get_verify_result() function is not used the certificated is trusted always and it can not be ensured that the certificate satisfies all necessary security requirements. This could allow an attacker to use an invalid certificate to claim to be a trusted host, use expired certificates, or conduct other attacks that could be detected if the certificate is properly validated. This issue affects OTRS: from 7.0.X before 7.0.47, from 8.0.X before 8.0.37; ((OTRS)) Community Edition: from 6.0.X through 6.0.34.

In versions of NGINX Controller prior to 3.2.0, communication between NGINX Controller and NGINX Plus instances skip TLS verification by default.

A flaw was found in the python-scciclient when making an HTTPS connection to a server where the server's certificate would not be verified. This issue opens up the connection to possible Man-in-the-middle (MITM) attacks.

The kantan netprint App for Android 2.0.3 and earlier does not verify X.509 certificates from servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

It was discovered that the sls-logging was not verifying hostnames in TLS certificates due to a misuse of the javax.net.ssl.SSLSocketFactory API. A malicious attacker in a privileged network position could abuse this to perform a man-in-the-middle attack. A successful man-in-the-middle attack would allow them to intercept, read, or modify network communications to and from the affected service. In the case of AtlasDB, the vulnerability was mitigated by other network controls such as two-way TLS when deployed as part of a Palantir platform. Palantir still recommends upgrading to a non-vulnerable version out of an abundance of caution.

A vulnerability in the SSL/TLS implementation of Cisco Nexus Dashboard could allow an unauthenticated, remote attacker to alter communications with associated controllers or view sensitive information. This vulnerability exists because SSL server certificates are not validated when Cisco Nexus Dashboard is establishing a connection to Cisco Application Policy Infrastructure Controller (APIC), Cisco Cloud APIC, or Cisco Nexus Dashboard Fabric Controller, formerly Data Center Network Manager (DCNM) controllers. An attacker could exploit this vulnerability by using man-in-the-middle techniques to intercept the traffic between the affected device and the controllers, and then using a crafted certificate to impersonate the controllers. A successful exploit could allow the attacker to alter communications between devices or view sensitive information, including Administrator credentials for these controllers.

Icinga 2 v2.8.0 through v2.11.7 and v2.12.2 has an issue where revoked certificates due for renewal will automatically be renewed, ignoring the CRL. This issue is fixed in Icinga 2 v2.11.8 and v2.12.3.

Missing SSL certificate validation in HTTPie v3.2.2 allows attackers to eavesdrop on communications between the host and server via a man-in-the-middle attack.

An Improper Certificate Validation weakness in the Juniper Networks Junos OS allows an attacker to perform Person-in-the-Middle (PitM) attacks when a system script is fetched from a remote source at a specified HTTPS URL, which may compromise the integrity and confidentiality of the device. The following command can be executed by an administrator via the CLI to refresh a script from a remote location, which is affected from this vulnerability: >request system scripts refresh-from (commit | event | extension-service | op | snmp) file filename url <https-url> This issue affects: Juniper Networks Junos OS All versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R2-S3, 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R3-S7; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2; 21.1 versions prior to 21.1R1-S1, 21.1R2.

Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a "type confusion" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.

The contribution feature in Zamboni 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 use of the Python urllib2 library.

Envoy is an open source edge and service proxy, designed for cloud-native applications. Envoy's tls allows re-use when some cert validation settings have changed from their default configuration. The only workaround for this issue is to ensure that default tls settings are used. Users are advised to upgrade.

Accepting arbitrary Subject Alternative Name (SAN) types, unless a PKI is specifically defined to use a particular SAN type, can result in bypassing name-constrained intermediates. Node.js < 12.22.9, < 14.18.3, < 16.13.2, and < 17.3.1 was accepting URI SAN types, which PKIs are often not defined to use. Additionally, when a protocol allows URI SANs, Node.js did not match the URI correctly.Versions of Node.js with the fix for this disable the URI SAN type when checking a certificate against a hostname. This behavior can be reverted through the --security-revert command-line option.

The client applications in 3CX on Windows, the 3CX app for iOS, and the 3CX application for Android through 2022-03-17 lack SSL certificate validation.

e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.

A vulnerability has been identified in SINUMERIK Edge (All versions < V3.2). The affected software does not properly validate the server certificate when initiating a TLS connection. This could allow an attacker to spoof a trusted entity by interfering in the communication path between the client and the intended server.

An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. The X.509 certificate validation can be skipped for a TLS-based e-mail server.

Incorrect validation of the TLS SNI hostname in osquery versions after 2.9.0 and before 4.2.0 could allow an attacker to MITM osquery traffic in the absence of a configured root chain of trust.

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.

Faye before version 1.4.0, there is a lack of certification validation in TLS handshakes. Faye uses em-http-request and faye-websocket in the Ruby version of its client. Those libraries both use the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname. That means that any `https:` or `wss:` connection made using these libraries is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. The first request a Faye client makes is always sent via normal HTTP, but later messages may be sent via WebSocket. Therefore it is vulnerable to the same problem that these underlying libraries are, and we needed both libraries to support TLS verification before Faye could claim to do the same. Your client would still be insecure if its initial HTTPS request was verified, but later WebSocket connections were not. This is fixed in Faye v1.4.0, which enables verification by default. For further background information on this issue, please see the referenced GitHub Advisory.

In GNOME glib-networking through 2.64.2, the implementation of GTlsClientConnection skips hostname verification of the server's TLS certificate if the application fails to specify the expected server identity. This is in contrast to its intended documented behavior, to fail the certificate verification. Applications that fail to provide the server identity, including Balsa before 2.5.11 and 2.6.x before 2.6.1, accept a TLS certificate if the certificate is valid for any host.

EM-HTTP-Request 1.1.5 uses the library eventmachine in an insecure way that allows an attacker to perform a man-in-the-middle attack against users of the library. The hostname in a TLS server certificate is not verified.

An issue was discovered in Pulse Secure Pulse Connect Secure (PCS) through 2020-04-06. The applet in tncc.jar, executed on macOS, Linux, and Solaris clients when a Host Checker policy is enforced, accepts an arbitrary SSL certificate.

A vulnerability in the certificate validation of Cisco&nbsp;Expressway-C and Cisco&nbsp;TelePresence VCS could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data.&nbsp;&nbsp;The vulnerability is due to a lack of validation of the SSL server certificate that an affected device receives when it establishes a connection to a Cisco&nbsp;Unified Communications Manager device. An attacker could exploit this vulnerability by using a man-in-the-middle technique to intercept the traffic between the devices, and then using a self-signed certificate to impersonate the endpoint. A successful exploit could allow the attacker to view the intercepted traffic in clear text or alter the contents of the traffic. Note: Cisco&nbsp;Expressway-E is not affected by this vulnerability.Cisco&nbsp;has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Heimdal Thor Agent 2.5.17x before 2.5.173 does not verify X.509 certificates from TLS servers, which allows remote attackers to spoof servers and obtain sensitive information via a crafted certificate.

On versions 15.0.0-15.0.1.1, the BIG-IP ASM Cloud Security Services profile uses a built-in verification mechanism that fails to properly authenticate the X.509 certificate of remote endpoints.

The NTV News24 prior to Ver.3.0.0 does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Apache Sling Commons Messaging Mail provides a simple layer on top of JavaMail/Jakarta Mail for OSGi to send mails via SMTPS. To reduce the risk of "man in the middle" attacks additional server identity checks must be performed when accessing mail servers. For compatibility reasons these additional checks are disabled by default in JavaMail/Jakarta Mail. The SimpleMailService in Apache Sling Commons Messaging Mail 1.0 lacks an option to enable these checks for the shared mail session. A user could enable these checks nevertheless by accessing the session via the message created by SimpleMessageBuilder and setting the property mail.smtps.ssl.checkserveridentity to true. Apache Sling Commons Messaging Mail 2.0 adds support for enabling server identity checks and these checks are enabled by default. - https://javaee.github.io/javamail/docs/SSLNOTES.txt - https://javaee.github.io/javamail/docs/api/com/sun/mail/smtp/package-summary.html - https://github.com/eclipse-ee4j/mail/issues/429

software-properties was vulnerable to a person-in-the-middle attack due to incorrect TLS certificate validation in softwareproperties/ppa.py. software-properties didn't check TLS certificates under python2 and only checked certificates under python3 if a valid certificate bundle was provided. Fixed in software-properties version 0.92.

An issue has been found in PowerDNS Recursor versions 4.1.x before 4.1.9 where records in the answer section of responses received from authoritative servers with the AA flag not set were not properly validated, allowing an attacker to bypass DNSSEC validation.

The "Apache NetBeans" autoupdate system does not validate SSL certificates and hostnames for https based downloads. This allows an attacker to intercept downloads of autoupdates and modify the download, potentially injecting malicious code. “Apache NetBeans" versions up to and including 11.2 are affected by this vulnerability.

A vulnerability in the Cisco Network Plug-and-Play (PnP) agent of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data. The vulnerability exists because the affected software insufficiently validates certificates. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt and modify confidential information on user connections to the affected software.

A vulnerability in the certificate handling component of the Cisco SPA112, SPA525, and SPA5X5 Series IP Phones could allow an unauthenticated, remote attacker to listen to or control some aspects of a Transport Level Security (TLS)-encrypted Session Initiation Protocol (SIP) conversation. The vulnerability is due to the improper validation of server certificates. An attacker could exploit this vulnerability by crafting a malicious server certificate to present to the client. An exploit could allow an attacker to eavesdrop on TLS-encrypted traffic and potentially route or redirect calls initiated by an affected device. Affected software include version 7.6.2 of the Cisco Small Business SPA525 Series IP Phones and Cisco Small Business SPA5X5 Series IP Phones and version 1.4.2 of the Cisco Small Business SPA500 Series IP Phones and Cisco Small Business SPA112 Series IP Phones.

Jenkins Spira Importer Plugin 3.2.3 and earlier disables SSL/TLS certificate validation for the Jenkins master JVM.

Open Build Service before version 0.165.4 diddn't validate TLS certificates for HTTPS connections with the osc client binary

A vulnerability, in The ReportsTrustManager class of Brocade SANnav versions before v2.0, could allow an attacker to perform a man-in-the-middle attack against Secure Sockets Layer(SSL)connections.

The Twitter Kit framework through 3.4.2 for iOS does not properly validate the api.twitter.com SSL certificate. Although the certificate chain must contain one of a set of pinned certificates, there are certain implementation errors such as a lack of hostname verification. NOTE: this is an end-of-life product.

OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.

ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.

Affected versions of CODESYS Git in Versions prior to V1.1.0.0 lack certificate validation in HTTPS handshakes. CODESYS Git does not implement certificate validation by default, so it does not verify that the server provides a valid and trusted HTTPS certificate. Since the certificate of the server to which the connection is made is not properly verified, the server connection is vulnerable to a man-in-the-middle attack.

The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a "purpose" has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named "purpose" values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. OpenSSL versions 1.1.1h and newer are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1h-1.1.1j).