Mozilla Network Security Services (NSS) before 3.12.3, Firefox before 3.0.13, Thunderbird before 2.0.0.23, and SeaMonkey before 1.1.18 do not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority. NOTE: this was originally reported for Firefox before 3.5.

In LemonLDAP::NG (aka lemonldap-ng) through 2.0.8, validity of the X.509 certificate is not checked by default when connecting to remote LDAP backends, because the default configuration of the Net::LDAPS module for Perl is used.

The _gnutls_x509_verify_certificate function in lib/x509/verify.c in libgnutls in GnuTLS before 2.6.1 trusts certificate chains in which the last certificate is an arbitrary trusted, self-signed certificate, which allows man-in-the-middle attackers to insert a spoofed certificate for any Distinguished Name (DN).

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 apt package in Debian jessie before 1.0.9.8.4, in Debian unstable before 1.4~beta2, in Ubuntu 14.04 LTS before 1.0.1ubuntu2.17, in Ubuntu 16.04 LTS before 1.2.15ubuntu0.2, and in Ubuntu 16.10 before 1.3.2ubuntu0.1 allows man-in-the-middle attackers to bypass a repository-signing protection mechanism by leveraging improper error handling when validating InRelease file signatures.

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.

Oracle MySQL before 5.7.3, Oracle MySQL Connector/C (aka libmysqlclient) before 6.1.3, and MariaDB before 5.5.44 use the --ssl option to mean that SSL is optional, which allows man-in-the-middle attackers to spoof servers via a cleartext-downgrade attack, aka a "BACKRONYM" attack.

The TLS stack in Mono before 3.12.1 allows man-in-the-middle attackers to conduct message skipping attacks and consequently impersonate clients by leveraging missing handshake state validation, aka a "SMACK SKIP-TLS" issue.

The TLS stack in Mono before 3.12.1 allows remote attackers to have unspecified impact via vectors related to client-side SSLv2 fallback.

GnuTLS before 3.3.13 does not validate that the signature algorithms match when importing a certificate.

An issue was discovered in Prosody before 0.11.9. The undocumented dialback_without_dialback option in mod_dialback enables an experimental feature for server-to-server authentication. It does not correctly authenticate remote server certificates, allowing a remote server to impersonate another server (when this option is enabled).

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.

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 Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.

LibreOffice supports digital signatures of ODF documents and macros within documents, presenting visual aids that no alteration of the document occurred since the last signing and that the signature is valid. An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to create a digitally signed ODF document, by manipulating the documentsignatures.xml or macrosignatures.xml stream within the document to combine multiple certificate data, which when opened caused LibreOffice to display a validly signed indicator but whose content was unrelated to the signature shown. This issue affects: The Document Foundation LibreOffice 7-0 versions prior to 7.0.6; 7-1 versions prior to 7.1.2.

Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL certificate verification when using the "Register with a Provider" flow.

If the Node.js https API was used incorrectly and "undefined" was in passed for the "rejectUnauthorized" parameter, no error was returned and connections to servers with an expired certificate would have been accepted.

When using an OCSP responder Apache Tomcat Native 1.2.0 to 1.2.16 and 1.1.23 to 1.1.34 did not correctly handle invalid responses. This allowed for revoked client certificates to be incorrectly identified. It was therefore possible for users to authenticate with revoked certificates when using mutual TLS. Users not using OCSP checks are not affected by this vulnerability.

duplicity 0.6.24 has improper verification of SSL certificates

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 parsing the AIA-Extension field of a client certificate, Apache Tomcat Native Connector 1.2.0 to 1.2.14 and 1.1.23 to 1.1.34 did not correctly handle fields longer than 127 bytes. The result of the parsing error was to skip the OCSP check. It was therefore possible for client certificates that should have been rejected (if the OCSP check had been made) to be accepted. Users not using OCSP checks are not affected by this vulnerability.

HTTPSConnections in OpenStack Keystone 2013, OpenStack Compute 2013.1, and possibly other OpenStack components, fail to validate server-side SSL certificates.

Mozilla Firefox before 19.0, Firefox ESR 17.x before 17.0.3, Thunderbird before 17.0.3, Thunderbird ESR 17.x before 17.0.3, and SeaMonkey before 2.16 allow man-in-the-middle attackers to spoof the address bar by operating a proxy server that provides a 407 HTTP status code accompanied by web script, as demonstrated by a phishing attack on an HTTPS site.

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.

nuSOAP before 0.7.3-5 does not properly check the hostname of a cert.

Go before 1.12.16 and 1.13.x before 1.13.7 (and the crypto/cryptobyte package before 0.0.0-20200124225646-8b5121be2f68 for Go) allows attacks on clients (resulting in a panic) via a malformed X.509 certificate.

Inappropriate implementation in WebRTC in Google Chrome prior to 84.0.4147.89 allowed an attacker in a privileged network position to leak cross-origin data via a crafted HTML page.

An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.

An issue was discovered in Arm Mbed TLS before 2.24.0. It incorrectly uses a revocationDate check when deciding whether to honor certificate revocation via a CRL. In some situations, an attacker can exploit this by changing the local clock.

In SaltStack Salt before 3002.5, when authenticating to services using certain modules, the SSL certificate is not always validated.

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

NetworkManager 0.9 and earlier allows local users to use other users' certificates or private keys when making a connection via the file path when adding a new connection.

PostgreSQL 8.4.x before 8.4.11, 9.0.x before 9.0.7, and 9.1.x before 9.1.3 truncates the common name to only 32 characters when verifying SSL certificates, which allows remote attackers to spoof connections when the host name is exactly 32 characters.

An issue was discovered in Qt before 5.15.15, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.2. Certificate validation for TLS does not always consider whether the root of a chain is a configured CA certificate.

Improper Certificate Validation in Node.js 10, 12, and 13 causes the process to abort when sending a crafted X.509 certificate

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.

Apache Tomcat Native 1.2.0 to 1.2.16 and 1.1.23 to 1.1.34 has a flaw that does not properly check OCSP pre-produced responses, which are lists (multiple entries) of certificate statuses. Subsequently, revoked client certificates may not be properly identified, allowing for users to authenticate with revoked certificates to connections that require mutual TLS. Users not using OCSP checks are not affected by this vulnerability.

The host name verification when using TLS with the WebSocket client was missing. It is now enabled by default. Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.9, 8.5.0 to 8.5.31, 8.0.0.RC1 to 8.0.52, and 7.0.35 to 7.0.88.

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.

Apache Thrift Java client library versions 0.5.0 through 0.11.0 can bypass SASL negotiation isComplete validation in the org.apache.thrift.transport.TSaslTransport class. An assert used to determine if the SASL handshake had successfully completed could be disabled in production settings making the validation incomplete.

Node.js < 12.22.9, < 14.18.3, < 16.13.2, and < 17.3.1 did not handle multi-value Relative Distinguished Names correctly. Attackers could craft certificate subjects containing a single-value Relative Distinguished Name that would be interpreted as a multi-value Relative Distinguished Name, for example, in order to inject a Common Name that would allow bypassing the certificate subject verification.Affected versions of Node.js that do not accept multi-value Relative Distinguished Names and are thus not vulnerable to such attacks themselves. However, third-party code that uses node's ambiguous presentation of certificate subjects may be vulnerable.

Node.js < 12.22.9, < 14.18.3, < 16.13.2, and < 17.3.1 converts SANs (Subject Alternative Names) to a string format. It uses this string to check peer certificates against hostnames when validating connections. The string format was subject to an injection vulnerability when name constraints were used within a certificate chain, allowing the bypass of these name constraints.Versions of Node.js with the fix for this escape SANs containing the problematic characters in order to prevent the injection. This behavior can be reverted through the --security-revert command-line option.

Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. In versions 2.5.0 through 2.13.0, ElasticsearchWriter, GelfWriter, InfluxdbWriter and Influxdb2Writer do not verify the server's certificate despite a certificate authority being specified. Icinga 2 instances which connect to any of the mentioned time series databases (TSDBs) using TLS over a spoofable infrastructure should immediately upgrade to version 2.13.1, 2.12.6, or 2.11.11 to patch the issue. Such instances should also change the credentials (if any) used by the TSDB writer feature to authenticate against the TSDB. There are no workarounds aside from upgrading.

An exploitable denial of service vulnerability exists within the reading of proprietary server certificates in FreeRDP 2.0.0-beta1+android11. A specially crafted challenge packet can cause the program termination leading to a denial of service condition. An attacker can compromise the server or use man in the middle to trigger this vulnerability.

dirmngr before 2.1.0 improperly handles certain system calls, which allows remote attackers to cause a denial of service (DOS) via a specially-crafted certificate.

LibreOffice supports digital signatures of ODF documents and macros within documents, presenting visual aids that no alteration of the document occurred since the last signing and that the signature is valid. An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to modify a digitally signed ODF document to insert an additional signing time timestamp which LibreOffice would incorrectly present as a valid signature signed at the bogus signing time. This issue affects: The Document Foundation LibreOffice 7-0 versions prior to 7.0.6; 7-1 versions prior to 7.1.2.

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).

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.

Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-middle attack which could leak any log messages sent through that appender. Fixed in Apache Log4j 2.12.3 and 2.13.1