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.

Duplicate of CVE-2024-45806.

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send HTTP/2 requests that write to the heap outside of the request buffers when the upstream is HTTP/1. This may be used to corrupt nearby heap contents (leading to a query-of-death scenario) or may be used to bypass Envoy's access control mechanisms such as path based routing. An attacker can also modify requests from other users that happen to be proximal temporally and spatially.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, escalation of privileges is possible when `failure_mode_allow: true` is configured for `ext_authz` filter. For affected components that are used for logging and/or visibility, requests may not be logged by the receiving service. When Envoy was configured to use ext_authz, ext_proc, tap, ratelimit filters, and grpc access log service and an http header with non-UTF-8 data was received, Envoy would generate an invalid protobuf message and send it to the configured service. The receiving service would typically generate an error when decoding the protobuf message. For ext_authz that was configured with ``failure_mode_allow: true``, the request would have been allowed in this case. For the other services, this could have resulted in other unforeseen errors such as a lack of visibility into requests. As of versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy by default sanitizes the values sent in gRPC service calls to be valid UTF-8, replacing data that is not valid UTF-8 with a `!` character. This behavioral change can be temporarily reverted by setting runtime guard `envoy.reloadable_features.service_sanitize_non_utf8_strings` to false. As a workaround, one may set `failure_mode_allow: false` for `ext_authz`.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, a malicious client is able to construct credentials with permanent validity in some specific scenarios. This is caused by the some rare scenarios in which HMAC payload can be always valid in OAuth2 filter's check. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, avoid wildcards/prefix domain wildcards in the host's domain configuration.

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions Envoy does not restrict the set of certificates it accepts from the peer, either as a TLS client or a TLS server, to only those certificates that contain the necessary extendedKeyUsage (id-kp-serverAuth and id-kp-clientAuth, respectively). This means that a peer may present an e-mail certificate (e.g. id-kp-emailProtection), either as a leaf certificate or as a CA in the chain, and it will be accepted for TLS. This is particularly bad when combined with the issue described in pull request #630, in that it allows a Web PKI CA that is intended only for use with S/MIME, and thus exempted from audit or supervision, to issue TLS certificates that will be accepted by Envoy. As a result Envoy will trust upstream certificates that should not be trusted. There are no known workarounds to this issue. Users are advised to upgrade.

Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows OCSP designated-responder authorization bypass via missing signature verification. The OCSP response validation in public_key:pkix_ocsp_validate/5 does not verify that a CA-designated responder certificate was cryptographically signed by the issuing CA. Instead, it only checks that the responder certificate's issuer name matches the CA's subject name and that the certificate has the OCSPSigning extended key usage. An attacker who can intercept or control OCSP responses can create a self-signed certificate with a matching issuer name and the OCSPSigning EKU, and use it to forge OCSP responses that mark revoked certificates as valid. This affects SSL/TLS clients using OCSP stapling, which may accept connections to servers with revoked certificates, potentially transmitting sensitive data to compromised servers. Applications using the public_key:pkix_ocsp_validate/5 API directly are also affected, with impact depending on usage context. This vulnerability is associated with program files lib/public_key/src/pubkey_ocsp.erl and program routines pubkey_ocsp:is_authorized_responder/3. This issue affects OTP from OTP 27.0 until OTP 28.4.2 and 27.3.4.10 corresponding to public_key from 1.16 until 1.20.3 and 1.17.1.2, and ssl from 11.2 until 11.5.4 and 11.2.12.7.

Sunshine is a self-hosted game stream host for Moonlight. In versions prior to 2026.516.143833, the client-certificate authentication can be bypassed because of how OpenSSL verification results are handled. In src/crypto.cpp, the custom verify callback treats X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, X509_V_ERR_CERT_NOT_YET_VALID, and X509_V_ERR_CERT_HAS_EXPIRED as success. This can allow an untrusted certificate to pass authentication and access protected HTTPS endpoints. This issue has been fixed in version 2026.516.143833.

Nanoleaf firmware v7.1.1 and below is missing TLS verification, allowing attackers to execute arbitrary code via a DNS hijacking attack.

Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. The TLS certificate validation in all Icinga 2 versions starting from 2.4.0 was flawed, allowing an attacker to impersonate both trusted cluster nodes as well as any API users that use TLS client certificates for authentication (ApiUser objects with the client_cn attribute set). This vulnerability has been fixed in v2.14.3, v2.13.10, v2.12.11, and v2.11.12.

core/imap/MCIMAPSession.cpp in Canary Mail before 3.22 has Missing SSL Certificate Validation for IMAP in STARTTLS mode.

Samsung Galaxy Apps before 4.4.01.7 allows modification of the hostname used for load balancing on installations of applications through a man-in-the-middle attack. An attacker may trick Galaxy Apps into using an arbitrary hostname for which the attacker can provide a valid SSL certificate, and emulate the API of the app store to modify existing apps at installation time. The specific flaw involves an HTTP method to obtain the load-balanced hostname that enforces SSL only after obtaining a hostname from the load balancer, and a missing app signature validation in the application XML. An attacker can exploit this vulnerability to achieve Remote Code Execution on the device. The Samsung ID is SVE-2018-12071.

systemd 239 through 245 accepts any certificate signed by a trusted certificate authority for DNS Over TLS. Server Name Indication (SNI) is not sent, and there is no hostname validation with the GnuTLS backend. NOTE: This has been disputed by the developer as not a vulnerability since hostname validation does not have anything to do with this issue (i.e. there is no hostname to be sent)

A vulnerability has been identified in SINUMERIK Analyse MyCondition (All versions), SINUMERIK Analyze MyPerformance (All versions), SINUMERIK Analyze MyPerformance /OEE-Monitor (All versions), SINUMERIK Analyze MyPerformance /OEE-Tuning (All versions), SINUMERIK Integrate Client 02 (All versions >= V02.00.12 < 02.00.18), SINUMERIK Integrate Client 03 (All versions >= V03.00.12 < 03.00.18), SINUMERIK Integrate Client 04 (V04.00.02 and all versions >= V04.00.15 < 04.00.18), SINUMERIK Integrate for Production 4.1 (All versions < V4.1 SP10 HF3), SINUMERIK Integrate for Production 5.1 (V5.1), SINUMERIK Manage MyMachines (All versions), SINUMERIK Manage MyMachines /Remote (All versions), SINUMERIK Manage MyMachines /Spindel Monitor (All versions), SINUMERIK Manage MyPrograms (All versions), SINUMERIK Manage MyResources /Programs (All versions), SINUMERIK Manage MyResources /Tools (All versions), SINUMERIK Manage MyTools (All versions), SINUMERIK Operate V4.8 (All versions < V4.8 SP8), SINUMERIK Operate V4.93 (All versions < V4.93 HF7), SINUMERIK Operate V4.94 (All versions < V4.94 HF5), SINUMERIK Optimize MyProgramming /NX-Cam Editor (All versions). Due to an error in a third-party dependency the ssl flags used for setting up a TLS connection to a server are overwitten with wrong settings. This results in a missing validation of the server certificate and thus in a possible TLS MITM szenario.

Improper certificate validation in Ivanti EPMM before versions 12.6.1.1, 12.7.0.1, and 12.8.0.1 allows a remote unauthenticated attacker to enroll a device belonging to a restricted set of unenrolled devices, leading to information disclosure about EPMM appliance and impacting on the integrity of the newly enrolled device identity.

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.

A certificate validation issue existed in the handling of WKWebView. This issue was addressed with improved validation. This issue is fixed in tvOS 16.1, iOS 16.1 and iPadOS 16, macOS Ventura 13, watchOS 9.1. Processing a maliciously crafted certificate may lead to arbitrary code execution.

An issue was discovered in VirusTotal. A maliciously crafted Universal/fat binary can evade third-party code signing checks. By not completing full inspection of the Universal/fat binary, the user of the third-party tool will believe that the code is signed by Apple, but the malicious unsigned code will execute.

An issue was discovered in Yelp OSXCollector. A maliciously crafted Universal/fat binary can evade third-party code signing checks. By not completing full inspection of the Universal/fat binary, the user of the third-party tool will believe that the code is signed by Apple, but the malicious unsigned code will execute.

An issue was discovered in Objective-See KnockKnock, LuLu, TaskExplorer, WhatsYourSign, and procInfo. A maliciously crafted Universal/fat binary can evade third-party code signing checks. By not completing full inspection of the Universal/fat binary, the user of the third-party tool will believe that the code is signed by Apple, but the malicious unsigned code will execute.

A man in the middle vulnerability exists in Jenkins vSphere Plugin 2.16 and older in VSphere.java that disables SSL/TLS certificate validation by default.

brianleroux tiny-json-http version all versions since commit 9b8e74a232bba4701844e07bcba794173b0238a8 (Oct 29 2016) contains a Missing SSL certificate validation vulnerability in The libraries core functionality is affected. that can result in Exposes the user to man-in-the-middle attacks.

An improper certificate validation vulnerability [CWE-295] in FortiOS 7.2.0 through 7.2.3, 7.0.0 through 7.0.7, 6.4 all versions, 6.2 all versions, 6.0 all versions and FortiProxy 7.0.0 through 7.0.6, 2.0 all versions, 1.2 all versions may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the FortiOS/FortiProxy device and remote servers hosting threat feeds (when the latter are configured as Fabric connectors in FortiOS/FortiProxy)

A vulnerability in the integration of single sign-on (SSO) with Control Hub in Cisco Webex Services could have allowed an unauthenticated, remote attacker to impersonate any user within the service. This vulnerability existed because of improper certificate validation. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by connecting to a service endpoint and supplying a crafted token. A successful exploit could have allowed the attacker to gain unauthorized access to legitimate Cisco Webex services.

An issue was discovered in Mbed TLS 3.x before 3.6.1. With TLS 1.3, when a server enables optional authentication of the client, if the client-provided certificate does not have appropriate values in if keyUsage or extKeyUsage extensions, then the return value of mbedtls_ssl_get_verify_result() would incorrectly have the MBEDTLS_X509_BADCERT_KEY_USAGE and MBEDTLS_X509_BADCERT_KEY_USAGE bits clear. As a result, an attacker that had a certificate valid for uses other than TLS client authentication would nonetheless be able to use it for TLS client authentication. Only TLS 1.3 servers were affected, and only with optional authentication (with required authentication, the handshake would be aborted with a fatal alert).

FastNetMon Community Edition through 1.2.9 does not verify TLS certificates on outbound HTTPS connections. The execute_web_request_secure() function in src/fast_library.cpp creates a boost::asio::ssl::context with tls_client mode and calls set_default_verify_paths() to load CA certificates, but never calls set_verify_mode(boost::asio::ssl::verify_peer). Without this call, OpenSSL performs the TLS handshake without validating the server's certificate chain, making all HTTPS connections vulnerable to man-in-the-middle attacks. This function is used for telemetry reporting to community-stats.fastnetmon.com, which sends system information including CPU model, kernel version, traffic statistics, and software configuration. An attacker can intercept and modify this data or redirect it to a malicious server.

OpenText BizManager before 16.6.0.1 does not perform proper validation during the change-password operation. This allows any authenticated user to change the password of any other user, including the Administrator account.

A weakness in the certificate validation logic of the deprecated IKEv1 key exchange may allow an unauthenticated attacker positioned as a man-in-the-middle to bypass certificate validation in VPN site-to-site connections that use certificate-based authentication. Successful exploitation could allow interception or modification of traffic traversing the VPN tunnel.

In Splunk Enterprise and Universal Forwarder versions before 9.0, the Splunk command-line interface (CLI) did not validate TLS certificates while connecting to a remote Splunk platform instance by default. After updating to version 9.0, see Configure TLS host name validation for the Splunk CLI https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation#Configure_TLS_host_name_validation_for_the_Splunk_CLI to enable the remediation. The vulnerability does not affect the Splunk Cloud Platform. At the time of publishing, we have no evidence of exploitation of this vulnerability by external parties. The issue requires conditions beyond the control of a potential bad actor such as a machine-in-the-middle attack. Hence, Splunk rates the complexity of the attack as High.

The httplib and urllib Python libraries that Splunk shipped with Splunk Enterprise did not validate certificates using the certificate authority (CA) certificate stores by default in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203. Python 3 client libraries now verify server certificates by default and use the appropriate CA certificate stores for each library. Apps and add-ons that include their own HTTP libraries are not affected. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

The (1) update and (2) package-installation features in MODX Revolution 2.5.4-pl and earlier do not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and trigger the execution of arbitrary code via a crafted certificate.

Splunk Enterprise peers in Splunk Enterprise versions before 9.0 and Splunk Cloud Platform versions before 8.2.2203 did not validate the TLS certificates during Splunk-to-Splunk communications by default. Splunk peer communications configured properly with valid certificates were not vulnerable. However, an attacker with administrator credentials could add a peer without a valid certificate and connections from misconfigured nodes without valid certificates did not fail by default. For Splunk Enterprise, update to Splunk Enterprise version 9.0 and Configure TLS host name validation for Splunk-to-Splunk communications (https://docs.splunk.com/Documentation/Splunk/9.0.0/Security/EnableTLSCertHostnameValidation) to enable the remediation.

Windows Secure Channel Spoofing Vulnerability

An Improper Certificate Validation vulnerability in the OPC-UA client and ANSL over TLS client used in Automation Studio versions before 6.5 could allow an unauthenticated attacker on the network to position themselves to intercept and interfere with data exchanges.

There is a vulnerability in the AP Certificate Management Service which could allow a threat actor to execute an unauthenticated RCE attack. Successful exploitation could allow an attacker to execute arbitrary commands on the underlying operating system leading to complete system compromise.

It was found that the Active Directory Plugin for Jenkins up to and including version 2.2 did not verify certificates of the Active Directory server, thereby enabling Man-in-the-Middle attacks.

A specially crafted x509 certificate can cause a single out of bounds byte overwrite in wolfSSL through 3.10.2 resulting in potential certificate validation vulnerabilities, denial of service and possible remote code execution. In order to trigger this vulnerability, the attacker needs to supply a malicious x509 certificate to either a server or a client application using this library.

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

It was found that jenkins-ssh-slaves-plugin before version 1.15 did not perform host key verification, thereby enabling Man-in-the-Middle attacks.

Improper Certificate Validation in Checkmk Exchange plugin MikroTik allows attackers in MitM position to intercept traffic. This issue affects MikroTik: from 2.0.0 through 2.5.5, from 0.4a_mk through 2.0a.

An exploitable free of a stack pointer vulnerability exists in the x509 certificate parsing code of ARM mbed TLS before 1.3.19, 2.x before 2.1.7, and 2.4.x before 2.4.2. A specially crafted x509 certificate, when parsed by mbed TLS library, can cause an invalid free of a stack pointer leading to a potential remote code execution. In order to exploit this vulnerability, an attacker can act as either a client or a server on a network to deliver malicious x509 certificates to vulnerable applications.

Improper validation of server certificates in Canon EOS Network Setting Tool Version 1.5.0 or earlier

Impact: undici's ProxyAgent silently drops the requestTls option when configured with a SOCKS5 proxy URI (socks5:// or socks://). The target HTTPS connection through the SOCKS5 tunnel falls back to Node's default trust store, ignoring user-configured ca, cert, key, rejectUnauthorized, and servername settings. Applications that pin to an internal or corporate CA via requestTls.ca will, when their proxy URI is SOCKS5, get the default Mozilla CA bundle as the trust anchor instead. Any cert signed by any publicly-trusted CA for the target hostname is accepted, breaking the intended pin and enabling MITM read and tamper of the HTTPS exchange. Affected applications are those that use undici's ProxyAgent (or Socks5ProxyAgent directly) with SOCKS5 AND rely on requestTls for TLS scope restriction. The bug was introduced in undici 7.23.0 when SOCKS5 support was added. Patches: Upgrade to undici v7.28.0 or v8.5.0. Workarounds: No workaround is available within the SOCKS5 path. If a SOCKS5 proxy with TLS scope restriction is required and an upgrade is not yet possible, route the traffic through an HTTP-proxy ProxyAgent instead, where requestTls is honored correctly.

Hutool v5.7.18's HttpRequest was discovered to ignore all TLS/SSL certificate validation.

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.

A vulnerability classified as critical has been found in cym1102 nginxWebUI up to 3.9.9. This affects the function handlePath of the file /adminPage/conf/saveCmd. The manipulation of the argument nginxPath leads to improper certificate validation. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-260577 was assigned to this vulnerability.

A flaw was found in assisted-migration-agent. The application hardcodes insecure Transport Layer Security (TLS) connections when communicating with vCenter. This vulnerability allows a Man-in-the-Middle (MITM) attacker to intercept and harvest vCenter administrator credentials. This can lead to unauthorized access to vCenter.

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.

In OCaml-TLS before 2.1.0, the server implementation does insufficient checks of the certificate provided by the client (when doing client authentication), which allows impersonation with certificates that are not meant for client authentication (because of KeyUsage and ExtendedKeyUsage).