Exposure of Sensitive Information to an Unauthorized Actor
Express-handlebars is a Handlebars view engine for Express. Express-handlebars mixes pure template data with engine configuration options through the Express render API. More specifically, the layout parameter may trigger file disclosure vulnerabilities in downstream applications. This potential vulnerability is somewhat restricted in that only files with existing extentions (i.e. file.extension) can be included, files that lack an extension will have .handlebars appended to them. For complete details refer to the referenced GHSL-2021-018 report. Notes in documentation have been added to help users avoid this potential information exposure vulnerability. This is fixed in 5.3.1
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.