Common TLS/SSL Issues And What They Mean | Cyberis Limited

Encryption implementation issues are, in my experience, some of the most commonly reported findings during penetration tests. Whilst they may not always be quite as scary as seeing "SQL Injection" or "Stored Cross-Site Scripting" in a report, their ubiquity merits some discussion. We broadly find the most often encountered issues fall under three categories: … Whilst it may be tempting to support older protocol versions, such as TLS 1.0 or even SSLv3, to maximise compatibility with legacy systems, this does not come without serious security compromises. Older protocol implementations can have inherent weaknesses that undermine the security they offer. They can lack support for modern encryption algorithms used in more secure cipher suites and may be missing features implemented in later versions, specifically designed to mitigate against the shortcomings of the older protocol. … ### Certificate Issues Certificate issues make the identification of genuine parties more difficult. TLS certificates are typically issued by a Certificate Authority (CA) who signs the certificate to confirm that it belongs to the owner of the domain name stated in the subject of the certificate. This allows a client’s browser to know it’s talking to the genuine server and not an impersonator (as is the case in man-in-the-middle attacks). … ### Weak Cipher Suites As cipher suites are what protocols use to encrypt data, the strength of the cryptography employed is paramount to ensure that the encryption is robust. If weak cipher suites are used, then the likelihood of the encryption being broken is greater which would eliminate the protections they afford. Resultantly, a suitably positioned attacker would be able to observe and edit any communication between two parties.