SES safely executes third-party JavaScript strict mode programs in compartments that have no excess authority in their global scope. Prior to version 1.12.0, web pages and web extensions using ses and the Compartment API to evaluate third-party code in an isolated execution environment that have also elsewhere used const, let, and class bindings in the top-level scope of a <script> tag will have inadvertently revealed these bindings in the lexical scope of third-party code. This issue has been patched in version 1.12.0. Workarounds for this issue involve either avoiding top-level let, const, or class bindings in <script> tags, or change these to var bindings to be reflected on globalThis.
The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.
Network-based products, such as web applications, often run on top of an operating system or similar environment. When the product communicates with outside parties, details about the underlying system are expected to remain hidden, such as path names for data files, other OS users, installed packages, the application environment, etc. This system information may be provided by the product itself, or buried within diagnostic or debugging messages. Debugging information helps an adversary learn about the system and form an attack plan. An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. Using other weaknesses, an attacker could cause errors to occur; the response to these errors can reveal detailed system information, along with other impacts. An attacker can use messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. A product may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.