A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality fail when multiple URLs are requested serially. Using its HSTS support, curl can be instructed to use HTTPS instead of usingan insecure clear-text HTTP step even when HTTP is provided in the URL. ThisHSTS mechanism would however surprisingly be ignored by subsequent transferswhen done on the same command line because the state would not be properlycarried on.

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.

When asking curl to use a `.netrc` file to find credentials and at the same time specifying a URL with a username(without a password), like `https://user@example.com/`, curl could wrongly get and use the password for *another* user set in the `.netrc` file for that host if such a one exists and there is no match for the specified user.

libcurl skips the certificate verification for a QUIC connection under certain conditions, when built to use wolfSSL. If told to use an unknown/bad cipher or curve, the error path accidentally skips the verification and returns OK, thus ignoring any certificate problems.

libcurl would reuse a previously created connection even when a TLS or SSHrelated option had been changed that should have prohibited reuse.libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse if one of them matches the setup. However, several TLS andSSH settings were left out from the configuration match checks, making themmatch too easily.

curl inadvertently kept the SSL session ID for connections in its cache even when the verify status (*OCSP stapling*) test failed. A subsequent transfer to the same hostname could then succeed if the session ID cache was still fresh, which then skipped the verify status check.

In curl and libcurl 7.52.0 to and including 7.53.1, libcurl would attempt to resume a TLS session even if the client certificate had changed. That is unacceptable since a server by specification is allowed to skip the client certificate check on resume, and may instead use the old identity which was established by the previous certificate (or no certificate). libcurl supports by default the use of TLS session id/ticket to resume previous TLS sessions to speed up subsequent TLS handshakes. They are used when for any reason an existing TLS connection couldn't be kept alive to make the next handshake faster. This flaw is a regression and identical to CVE-2016-5419 reported on August 3rd 2016, but affecting a different version range.

curl before 7.53.0 has an incorrect TLS Certificate Status Request extension feature that asks for a fresh proof of the server's certificate's validity in the code that checks for a test success or failure. It ends up always thinking there's valid proof, even when there is none or if the server doesn't support the TLS extension in question. This could lead to users not detecting when a server's certificate goes invalid or otherwise be mislead that the server is in a better shape than it is in reality. This flaw also exists in the command line tool (--cert-status).

When curl is told to use the Certificate Status Request TLS extension, often referred to as *OCSP stapling*, to verify that the server certificate is valid, it fails to detect OCSP problems and instead wrongly consider the response as fine.

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.

When doing TLS related transfers with reused easy or multi handles and altering the `CURLSSLOPT_NO_PARTIALCHAIN` option, libcurl could accidentally reuse a CA store cached in memory for which the partial chain option was reversed. Contrary to the user's wishes and expectations. This could make libcurl find and accept a trust chain that it otherwise would not.

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 exists in curl <v8.1.0 in the way it supports matching of wildcard patterns when listed as "Subject Alternative Name" in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS library. This private wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before used for certificate checks. Puny coded names always start with `xn--` and should not be allowed to pattern match, but the wildcard check in curl could still check for `x*`, which would match even though the IDN name most likely contained nothing even resembling an `x`.

When using `CURLOPT_PINNEDPUBLICKEY` option with libcurl or `--pinnedpubkey` with the curl tool,curl should check the public key of the server certificate to verify the peer. This check was skipped in a certain condition that would then make curl allow the connection without performing the proper check, thus not noticing a possible impostor. To skip this check, the connection had to be done with QUIC with ngtcp2 built to use GnuTLS and the user had to explicitly disable the standard certificate verification.

libcurl supports *pinning* of the server certificate public key for HTTPS transfers. Due to an omission, this check is not performed when connecting with QUIC for HTTP/3, when the TLS backend is wolfSSL. Documentation says the option works with wolfSSL, failing to specify that it does not for QUIC and HTTP/3. Since pinning makes the transfer succeed if the pin is fine, users could unwittingly connect to an impostor server without noticing.

When curl is told to use the Certificate Status Request TLS extension, often referred to as OCSP stapling, to verify that the server certificate is valid, it might fail to detect some OCSP problems and instead wrongly consider the response as fine. If the returned status reports another error than 'revoked' (like for example 'unauthorized') it is not treated as a bad certficate.

libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the `CURLOPT_SSLCERT` option (`--cert` with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the appliction runs with a current working directory that is writable by other users (like `/tmp`), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.

The libcurl CURLOPT_SSL_VERIFYPEER option was disabled on a subset of requests made by Nest production devices which enabled a potential man-in-the-middle attack on requests to Google cloud services by any host the traffic was routed through.

curl 7.41.0 through 7.73.0 is vulnerable to an improper check for certificate revocation due to insufficient verification of the OCSP response.

When a user invokes curl using a schemeless URL combined with `--proto-default` sftp (or scp), a disconnect occurs between the tool layer and libcurl. The tool layer incorrectly infers the URL scheme, which erroneously bypasses the initialization of critical SSH security options like CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the libcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes the connection via SFTP/SCP as specified. Because the tool layer skipped the security configuration, these SSH host verification options are silently omitted, causing curl to connect to an unverified SSH remote host without throwing an error.

The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."

When configured to use an SSL bundle, Spring Boot's RabbitMQ auto-configuration does not perform hostname verification when connecting to the RabbitMQ broker. Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14) per vendor advisory.

Improper certificate validation in Zoom Workplace for Linux before version 6.4.13 may allow an unauthorized user to conduct an information disclosure via network access.

A insecure configuration for certificate verification (http.verify_mode = OpenSSL::SSL::VERIFY_NONE) may lead to verification bypass in Red Hat CloudForms 5.x.

Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.

Botan is a C++ cryptography library. In 3.11.0, the function Certificate_Store::certificate_known had a misleading name; it would return true if any certificate in the store had a DN (and subject key identifier, if set) matching that of the argument. It did not check that the cert it found and the cert it was passed were actually the same certificate. In 3.11.0 an extension of path validation logic was made which assumed that certificate_known only returned true if the certificates were in fact identical. The impact is that if an end entity certificate is presented, and its DN (and subject key identifier, if set) match that of any trusted root, the end entity certificate is accepted immediately as if it itself were a trusted root. , This vulnerability is fixed in 3.11.1.

Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, `pki.verifyCertificateChain()` does not enforce RFC 5280 basicConstraints requirements when an intermediate certificate lacks both the `basicConstraints` and `keyUsage` extensions. This allows any leaf certificate (without these extensions) to act as a CA and sign other certificates, which node-forge will accept as valid. Version 1.4.0 patches the issue.

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.

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.

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.

Precision Bridge PrecisionBridge.exe (aka the thick client) before 7.3.21 allows an integrity violation in which the same license key is used on multiple systems, via vectors involving a Process Hacker memory dump, error message inspection, and modification of a MAC address.

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.

In JetBrains Ktor before 2.3.5 server certificates were not verified

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.

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.

An 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 impersonate registered Sentry hosts and obtain valid CA-signed client certificates.

Missing hash/digest size and OID checks allow digests smaller than allowed when verifying ECDSA certificates, or smaller than is appropriate for the relevant key type, to be accepted by signature verification functions. This could lead to reduced security of ECDSA certificate-based authentication if the public CA key used is also known. This affects ECDSA/ECC verification when EdDSA or ML-DSA is also enabled.

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).

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

Due to a lack of certificate validation, all traffic from the mobile application can be intercepted. As a result, an adversary located "upstream" can decrypt the TLS traffic, inspect its contents, and modify the requests in transit. This may result in a total compromise of the user's account if the attacker intercepts a request with active authentication tokens or cracks the MD5 hash sent on login.

Improper Input Validation vulnerability. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0-M1 through 9.0.112. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Older EOL versions are not affected. Tomcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one of those hosts did not require client certificate authentication but another one did, it was possible for a client to bypass the client certificate authentication by sending different host names in the SNI extension and the HTTP host header field. The vulnerability only applies if client certificate authentication is only enforced at the Connector. It does not apply if client certificate authentication is enforced at the web application. Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fix the issue.

Tonec Internet Download Manager 6.42.41.1 and earlier suffers from Missing SSL Certificate Validation, which allows attackers to bypass update protections.

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.

Potentially, SAP Cloud Connector, version - 2.0 communication with the backend is accepted without sufficient validation of the certificate.

WP-CLI is the command-line interface for WordPress. An improper error handling in HTTPS requests management in WP-CLI version 0.12.0 and later allows remote attackers able to intercept the communication to remotely disable the certificate verification on WP-CLI side, gaining full control over the communication content, including the ability to impersonate update servers and push malicious updates towards WordPress instances controlled by the vulnerable WP-CLI agent, or push malicious updates toward WP-CLI itself. The vulnerability stems from the fact that the default behavior of `WP_CLI\Utils\http_request()` when encountering a TLS handshake error is to disable certificate validation and retry the same request. The default behavior has been changed with version 2.5.0 of WP-CLI and the `wp-cli/wp-cli` framework (via https://github.com/wp-cli/wp-cli/pull/5523) so that the `WP_CLI\Utils\http_request()` method accepts an `$insecure` option that is `false` by default and consequently that a TLS handshake failure is a hard error by default. This new default is a breaking change and ripples through to all consumers of `WP_CLI\Utils\http_request()`, including those in separate WP-CLI bundled or third-party packages. https://github.com/wp-cli/wp-cli/pull/5523 has also added an `--insecure` flag to the `cli update` command to counter this breaking change. There is no direct workaround for the default insecure behavior of `wp-cli/wp-cli` versions before 2.5.0. The workaround for dealing with the breaking change in the commands directly affected by the new secure default behavior is to add the `--insecure` flag to manually opt-in to the previous insecure behavior.

In Botan before 2.19.3, it is possible to forge OCSP responses due to a certificate verification error. This issue was introduced in Botan 1.11.34 (November 2016).

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.

openssl_x509_check_ip_asc in lua-openssl 0.7.7-1 mishandles X.509 certificate validation because it uses lua_pushboolean for certain non-boolean return values.