The Twitter Kit framework through 3.4.2 for iOS does not properly validate the api.twitter.com SSL certificate. Although the certificate chain must contain one of a set of pinned certificates, there are certain implementation errors such as a lack of hostname verification. NOTE: this is an end-of-life product.

Multiple cross-site request forgery (CSRF) vulnerabilities in the iTwitter plugin 0.04 and earlier for WordPress allow remote attackers to hijack the authentication of administrators for requests that conduct cross-site scripting (XSS) attacks via the (1) itexttwitterusername or (2) itexttwitteruserpass parameter in the iTwitter.php page to wp-admin/options-general.php.

The Twittee Text Tweet WordPress plugin through 1.0.8 does not properly escape POST values which are printed back to the user inside one of the plugin's administrative page, which allows reflected XSS attacks targeting administrators to happen.

ServicesTwitter 0.6.3 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.

This vulnerability was caused by an incomplete fix to CVE-2017-0911. Twitter Kit for iOS versions 3.0 to 3.4.0 is vulnerable to a callback verification flaw in the "Login with Twitter" component allowing an attacker to provide alternate credentials. In the final step of "Login with Twitter" authentication information is passed back to the application using the registered custom URL scheme (typically twitterkit-<consumer-key>) on iOS. Because the callback handler did not verify the authenticity of the response, this step is vulnerable to forgery, potentially allowing attacker to associate a Twitter account with a third-party service.

server/handler/HistogramQueryHandler.scala in Twitter TwitterServer (aka twitter-server) before 20.12.0, in some configurations, allows XSS via the /histograms endpoint.