Spice, versions 0.5.2 through 0.14.1, are vulnerable to an out-of-bounds read due to an off-by-one error in memslot_get_virt. This may lead to a denial of service, or, in the worst case, code-execution by unauthenticated attackers.

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.

The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft Internet Information Services (IIS) 7.0, mod_ssl in the Apache HTTP Server 2.2.14 and earlier, OpenSSL before 0.9.8l, GnuTLS 2.8.5 and earlier, Mozilla Network Security Services (NSS) 3.12.4 and earlier, multiple Cisco products, and other products, does not properly associate renegotiation handshakes with an existing connection, which allows man-in-the-middle attackers to insert data into HTTPS sessions, and possibly other types of sessions protected by TLS or SSL, by sending an unauthenticated request that is processed retroactively by a server in a post-renegotiation context, related to a "plaintext injection" attack, aka the "Project Mogul" issue.

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.

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.

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).

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.

Apache Commons HttpClient 3.x, as used in Amazon Flexible Payments Service (FPS) merchant Java SDK and other products, 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.

Mark Laing discovered in LXD's PKI mode, until version 5.21.1, that a restricted certificate could be added to the trust store with its restrictions not honoured.

Mark Laing discovered that LXD's PKI mode, until version 5.21.2, could be bypassed if the client's certificate was present in the trust store.

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.

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.

It was discovered that Dovecot before versions 2.2.36.1 and 2.3.4.1 incorrectly handled client certificates. A remote attacker in possession of a valid certificate with an empty username field could possibly use this issue to impersonate other users.

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.

The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS store of CA certificates, which results in SSL connections succeeding in situations where a verification failure is the correct outcome. This is related to use of the ssl_context, ca_certs, or ca_certs_dir argument.

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.

When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an administrator.) This could have caused add-ons to become out-of-date silently without notification to the user. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

NETGEAR RAX30 Improper Certificate Validation Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of NETGEAR RAX30 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloading of files via HTTPS. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-19589.

An improper certification validation vulnerability in the Insider Threat Management (ITM) Agent for MacOS could be used by an anonymous actor on an adjacent network to establish a man-in-the-middle position between the agent and the ITM server after the agent has registered. All versions prior to 7.14.3.69 are affected. Agents for Windows, Linux, and Cloud are unaffected.

IBM Security Verify Access 10.0.0.0 through 10.0.6.1 uses insecure calls that could allow an attacker on the network to take control of the server. IBM X-Force ID: 254977.

A combination of a use of hard-coded cryptographic key vulnerability [CWE-321] in FortiClientEMS 7.0.1 and below, 6.4.6 and below and an improper certificate validation vulnerability [CWE-297] in FortiClientWindows, FortiClientLinux and FortiClientMac 7.0.1 and below, 6.4.6 and below may allow an unauthenticated and network adjacent attacker to perform a man-in-the-middle attack between the EMS and the FCT via the telemetry protocol.

PDF-XChange Editor Updater Improper Certificate Validation Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of PDF-XChange Editor. User interaction is not required to exploit this vulnerability. The specific flaw exists within the update functionality. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this vulnerability to execute code in the context of the current user. Was ZDI-CAN-22224.