CVE-2019-16263 in Twitter Kit Framework
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 01/03/2024
The vulnerability identified as CVE-2019-16263 affects the Twitter Kit framework version 3.4.2 and earlier for iOS platforms, representing a critical SSL certificate validation weakness that undermines the security of mobile applications integrating this library. This issue stems from improper implementation of SSL certificate validation mechanisms within the framework, specifically failing to conduct proper hostname verification despite maintaining certificate pinning functionality. The vulnerability exists in a product that has reached end-of-life status, meaning it no longer receives security updates or support from the vendor, which compounds the risk for organizations still utilizing deprecated components. The framework's certificate validation process maintains a set of pinned certificates but does not adequately verify that the certificate being presented matches the expected hostname, creating a potential avenue for man-in-the-middle attacks.
The technical flaw manifests in the framework's failure to properly validate the hostname associated with the SSL certificate presented by api.twitter.com during secure communications. While the implementation correctly maintains a certificate pinning mechanism that requires certificates to be part of a predefined set of trusted certificates, the absence of hostname verification creates a security gap that attackers can exploit. This weakness allows malicious actors to potentially substitute a valid certificate from the pinned set with a certificate issued for a different hostname, effectively bypassing the certificate validation process. The vulnerability is particularly concerning because it operates at the transport layer security level, where proper certificate validation is essential for maintaining the confidentiality and integrity of communications between mobile applications and remote services. This type of implementation error falls under the category of improper certificate validation as defined by CWE-295, which specifically addresses issues related to certificate validation and hostname verification in secure communications.
The operational impact of this vulnerability extends beyond simple certificate validation failures, creating potential security risks for mobile applications that rely on the Twitter Kit framework for social media integration. Applications using this framework may be susceptible to session hijacking, data interception, and other attacks that exploit the weakened SSL validation. The risk is particularly significant for applications handling sensitive user data or requiring secure communication channels, as the vulnerability could enable attackers to impersonate Twitter's services and potentially access user information or manipulate communications. Even though the framework is end-of-life, organizations that have not migrated away from this technology remain exposed to these risks, and the vulnerability could be exploited in environments where legacy systems continue to operate. This situation aligns with ATT&CK technique T1573.001, which covers the use of insecure communications protocols and certificate validation weaknesses to gain unauthorized access to systems or data.
Organizations should immediately cease use of the Twitter Kit framework version 3.4.2 and earlier, as no security patches are available for this end-of-life product. The recommended mitigation strategy involves migrating to supported alternatives that implement proper SSL certificate validation including hostname verification, such as newer versions of Twitter's official SDKs or alternative social media integration libraries. Security teams should conduct comprehensive audits of their mobile applications to identify any remaining dependencies on this deprecated framework and implement proper certificate pinning with hostname verification in all secure communication channels. Additionally, organizations should consider implementing network monitoring solutions to detect potential exploitation attempts targeting this vulnerability and ensure that all mobile applications maintain up-to-date security practices that include proper SSL/TLS implementation and validation. The vulnerability demonstrates the importance of maintaining current security practices and avoiding reliance on deprecated software components that no longer receive security updates or support from vendors.