An adversary takes advantage of incorrectly configured SSL communications that enables access to data intended to be encrypted. The adversary may also use this type of attack to inject commands or other traffic into the encrypted stream to cause compromise of either the client or server.
Likelihood Of Attack
The table below shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Meta Attack Pattern - A meta level attack pattern in CAPEC is a decidedly abstract characterization of a specific methodology or technique used in an attack. A meta attack pattern is often void of a specific technology or implementation and is meant to provide an understanding of a high level approach. A meta level attack pattern is a generalization of related group of standard level attack patterns. Meta level attack patterns are particularly useful for architecture and design level threat modeling exercises.
Determine the configuration levels of either the server or client being targeted, preferably both. This is not a hard requirement, as the attacker can simply assume commonly exploitable configuration settings and blindly attempt them.
Provide controlled access to the server by the client, by either providing a link for the client to click on, or by positioning one's self at a place on the network to intercept and control the flow of data between client and server, e.g. MITM (man in the middle).
Insert the malicious data into the stream that takes advantage of the configuration flaw.
Access to the client/server stream.
The attacker needs real-time access to network traffic in such a manner that the attacker can grab needed information from the SSL stream, possibly influence the decided-upon encryption method and options, and perform automated analysis to decipher encrypted material recovered. Tools exist to automate part of the tasks, but to successfully use these tools in an attack scenario requires detailed understanding of the underlying principles.
The attacker needs the ability to sniff traffic, and optionally be able to route said traffic to a system where the sniffing of traffic can take place, and act upon the recovered traffic in real time.
The table below specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Usage of configuration settings, such as stream ciphers vs. block ciphers and setting timeouts on SSL sessions to extremely low values lessens the potential impact. Use of later versions of TLS (e.g. TLS 1.1+) can also be effective, but not all clients or servers support the later versions.
Using MITM techniques, an attacker launches a blockwise chosen-boundary attack to obtain plaintext HTTP headers by taking advantage of an SSL session using an encryption protocol in CBC mode with chained initialization vectors (IV). This allows the attacker to recover session IDs, authentication cookies, and possibly other valuable data that can be used for further exploitation. Additionally this could allow for the insertion of data into the stream, allowing for additional attacks (CSRF, SQL inject, etc) to occur.
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.