An issue was discovered in the selinux-policy (aka Reference Policy) package 3.14 through 2020-08-24 because the .config/Yubico directory is mishandled. Consequently, when SELinux is in enforced mode, pam-u2f is not allowed to read the user's U2F configuration file. If configured with the nouserok option (the default when configured by the authselect tool), and that file cannot be read, the second factor is disabled. An attacker with only the knowledge of the password can then log in, bypassing 2FA.

In ectd before versions 3.4.10 and 3.3.23, gateway TLS authentication is only applied to endpoints detected in DNS SRV records. When starting a gateway, TLS authentication will only be attempted on endpoints identified in DNS SRV records for a given domain, which occurs in the discoverEndpoints function. No authentication is performed against endpoints provided in the --endpoints flag. This has been fixed in versions 3.4.10 and 3.3.23 with improved documentation and deprecation of the functionality.

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 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.

The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted.

It was found that nmcli, a command line interface to NetworkManager did not honour 802-1x.ca-path and 802-1x.phase2-ca-path settings, when creating a new profile. When a user connects to a network using this profile, the authentication does not happen and the connection is made insecurely.

An invalid authentication sequence could result in the hostapd process terminating due to missing state validation steps when processing the SAE confirm message when in hostapd/AP mode. All version of hostapd with SAE support are vulnerable. An attacker may force the hostapd process to terminate, performing a denial of service attack. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.7 are affected.

The implementations of EAP-PWD in wpa_supplicant EAP Peer, when built against a crypto library missing explicit validation on imported elements, do not validate the scalar and element values in EAP-pwd-Commit. An attacker may complete authentication, session key and control of the data connection with a client. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.4 are affected. Both hostapd with EAP-pwd support and wpa_supplicant with EAP-pwd support prior to and including version 2.7 are affected.

The implementations of EAP-PWD in hostapd EAP Server and wpa_supplicant EAP Peer do not validate the scalar and element values in EAP-pwd-Commit. This vulnerability may allow an attacker to complete EAP-PWD authentication without knowing the password. However, unless the crypto library does not implement additional checks for the EC point, the attacker will not be able to derive the session key or complete the key exchange. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.4 are affected. Both hostapd with EAP-pwd support and wpa_supplicant with EAP-pwd support prior to and including version 2.7 are affected.

The implementations of EAP-PWD in hostapd EAP Server, when built against a crypto library missing explicit validation on imported elements, do not validate the scalar and element values in EAP-pwd-Commit. An attacker may be able to use invalid scalar/element values to complete authentication, gaining session key and network access without needing or learning the password. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.4 are affected. Both hostapd with EAP-pwd support and wpa_supplicant with EAP-pwd support prior to and including version 2.7 are affected.

Clustered Data ONTAP versions 9.0 and higher do not enforce hostname verification under certain circumstances making them susceptible to impersonation via man-in-the-middle attacks.

An improper certificate validation vulnerability exists in the BIG-IP Edge Client for Windows and macOS and may allow an attacker to impersonate a BIG-IP APM system.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

IBM Cognos Analytics 11.2.0, 11.2.1, 11.2.2, 11.2.3, 11.2.4, 12.0.0, 12.0.1, and 12.0.2 is vulnerable to improper certificate validation when using the IBM Planning Analytics Data Source Connection. This could allow an attacker to spoof a trusted entity by interfering in the communication path between IBM Planning Analytics server and IBM Cognos Analytics server. IBM X-Force ID: 283364.

ovirt-engine-sdk-python before 3.4.0.7 and 3.5.0.4 does not verify that the hostname of the remote endpoint matches the Common Name (CN) or subjectAltName as specified by its x.509 certificate in a TLS/SSL session. This could allow man-in-the-middle attackers to spoof remote endpoints via an arbitrary valid certificate.

Improper validation of the server’s certificate chain in secure traffic scanning feature considered intermediate certificate signed using the MD5 or SHA1 algorithm as trusted.

A missing secure communication definition and an incomplete TLS validation in the upgrade service in B&R Automation Studio versions 4.0.x, 4.1.x, 4.2.x, < 4.3.11SP, < 4.4.9SP, < 4.5.5SP, < 4.6.4 and < 4.7.2 enable unauthenticated users to perform MITM attacks via the B&R upgrade server.

In fence-agents before 4.0.17 does not verify remote SSL certificates in the fence_cisco_ucs.py script which can potentially allow for man-in-the-middle attackers to spoof SSL servers via arbitrary SSL certificates.

Man-in-the-middle vulnerability in Micro Focus Self Service Password Reset, affecting all versions prior to 4.4.0.4. The vulnerability could exploit invalid certificate validation and may result in a man-in-the-middle attack.

OSS Http Request (Apache Cordova Plugin) 6 is affected by: Missing SSL certificate validation. The impact is: certificate spoofing. The component is: use this library when https communication. The attack vector is: certificate spoofing.

vdsm and vdsclient does not validate certficate hostname from another vdsm which could facilitate a man-in-the-middle attack

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.

On affected platforms running Arista EOS with 802.1x authentication configured on the access/trunk ports, and routing enabled on the access VLAN of the ports, a malicious supplicant may be able to bypass the requirement to perform 802.1x authentication.

The vulnerability have been reported to affect earlier versions of Helpdesk. If exploited, this improper certificate validation vulnerability could allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. QNAP has already fixed the issue in Helpdesk 3.0.3 and later.

The libwww-perl LWP::Protocol::https module 6.04 through 6.06 for Perl, when using IO::Socket::SSL as the SSL socket class, allows attackers to disable server certificate validation via the (1) HTTPS_CA_DIR or (2) HTTPS_CA_FILE environment variable.

matrix-nio is a Python Matrix client library, designed according to sans I/O principles. Prior to version 0.20, when a users requests a room key from their devices, the software correctly remember the request. Once they receive a forwarded room key, they accept it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.20 fixes the issue.

Matrix iOS SDK allows developers to build iOS apps compatible with Matrix. Prior to version 0.23.19, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. matrix-ios-sdk version 0.23.19 has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround. To avoid malicious backup attacks, one should not verify one's new logins using emoji/QR verifications methods until patched.

matrix-android-sdk2 is the Matrix SDK for Android. Prior to version 1.5.1, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. matrix-android-sdk2 would then additionally sign such a key backup with its device key, spilling trust over to other devices trusting the matrix-android-sdk2 device. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. matrix-android-sdk2 version 1.5.1 has been modified to only accept Olm-encrypted to-device messages and to stop signing backups on a successful decryption. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust, and matrix-sdk-crypto is the Matrix encryption library. Prior to version 0.6, when a user requests a room key from their devices, the software correctly remembers the request. When the user receives a forwarded room key, the software accepts it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.6 fixes this issue.

Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. Starting with version 19.7.0, matrix-js-sdk has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.

Matrix JavaScript SDK is the Matrix Client-Server software development kit (SDK) for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver could interfere with the verification flow between two users, injecting its own cross-signing user identity in place of one of the users’ identities. This would lead to the other device trusting/verifying the user identity under the control of the homeserver instead of the intended one. The vulnerability is a bug in the matrix-js-sdk, caused by checking and signing user identities and devices in two separate steps, and inadequately fixing the keys to be signed between those steps. Even though the attack is partly made possible due to the design decision of treating cross-signing user identities as Matrix devices on the server side (with their device ID set to the public part of the user identity key), no other examined implementations were vulnerable. Starting with version 19.7.0, the matrix-js-sdk has been modified to double check that the key signed is the one that was verified instead of just referencing the key by ID. An additional check has been made to report an error when one of the device ID matches a cross-signing key. As this attack requires coordination between a malicious homeserver and an attacker, those who trust their homeservers do not need a particular workaround.

D-Link DIR865L v1.03 suffers from an "Unauthenticated Hardware Linking" vulnerability.

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

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.

The Chase mobile banking application for Android 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 overriding the default X509TrustManager. NOTE: this vulnerability was fixed in the summer of 2012, but the version number was not changed or is not known.

Cisco IronPort Web Security Appliance does not check for certificate revocation which could lead to MITM attacks

The Apache Bookkeeper Java Client (before 4.14.6 and also 4.15.0) does not close the connection to the bookkeeper server when TLS hostname verification fails. This leaves the bookkeeper client vulnerable to a man in the middle attack. The problem affects BookKeeper client prior to versions 4.14.6 and 4.15.1.

The Certificate Trust Policy component in Apple Mac OS X before 10.6.8 does not perform CRL checking for Extended Validation (EV) certificates that lack OCSP URLs, which might allow man-in-the-middle attackers to spoof an SSL server via a revoked certificate.

Mercurial before 1.6.4 fails to verify the Common Name field of SSL certificates which allows remote attackers who acquire a certificate signed by a Certificate Authority to perform a man-in-the-middle attack.

offlineimap before 6.3.2 does not check for SSL server certificate validation when "ssl = yes" option is specified which can allow man-in-the-middle attacks.

An Improper Authentication vulnerability in Korenix JetNet TFTP allows abuse of this service. This issue affects JetNet devices older than firmware version 2024/01.

A Improper Certificate Validation vulnerability in susestudio-common of SUSE Studio onsite allows remote attackers to MITM connections to the repositories, which allows the modification of packages received over these connections. This issue affects: SUSE Studio onsite susestudio-common version 1.3.17-56.6.3 and prior versions.

IBM Concert 1.0.0 and 1.0.1 vulnerable to attacks that rely on the use of cookies without the SameSite attribute.

An exploitable vulnerability exists in the filtering functionality of Circle with Disney. SSL certificates for specific domain names can cause the Bluecoat library to accept a different certificate than intended. An attacker can host an HTTPS server with this certificate to trigger this vulnerability.

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.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 4.10.11 and 5.2.2, the certificate in the Parse Server Apple Game Center auth adapter not validated. As a result, authentication could potentially be bypassed by making a fake certificate accessible via certain Apple domains and providing the URL to that certificate in an authData object. Versions 4.0.11 and 5.2.2 prevent this by introducing a new `rootCertificateUrl` property to the Parse Server Apple Game Center auth adapter which takes the URL to the root certificate of Apple's Game Center authentication certificate. If no value is set, the `rootCertificateUrl` property defaults to the URL of the current root certificate as of May 27, 2022. Keep in mind that the root certificate can change at any time and that it is the developer's responsibility to keep the root certificate URL up-to-date when using the Parse Server Apple Game Center auth adapter. There are no known workarounds for this issue.

Pion DTLS is a Go implementation of Datagram Transport Layer Security. Prior to version 2.1.5, a DTLS Client could provide a Certificate that it doesn't posses the private key for and Pion DTLS wouldn't reject it. This issue affects users that are using Client certificates only. The connection itself is still secure. The Certificate provided by clients can't be trusted when using a Pion DTLS server prior to version 2.1.5. Users should upgrade to version 2.1.5 to receive a patch. There are currently no known workarounds.

IBM QRadar SIEM 7.5 could allow an unauthorized user to perform unauthorized actions due to improper certificate validation. IBM X-Force ID: 275706.

PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, on GnuTLS builds, the SIP TLS transport (sip_transport_tls) can accept connections with invalid or untrusted certificates even when the application explicitly enables certificate verification via verify_server = PJ_TRUE or verify_client = PJ_TRUE. This issue has been patched in version 2.17.