Highlight.js is a widely used JavaScript library for syntax highlighting in web pages, automatically detecting the language used in code snippets. Versions 9.18.5 and 9.18.4 are closely related, representing incremental updates to the library. Examining the provided data, the most notable differences lie in the build details and release dates. Version 9.18.5 was released on November 19, 2020, while 9.18.4 was released a day earlier on November 18, 2020. The unpacked size of version 9.18.5 is slightly larger at 1,442,583 bytes compared to 1,441,887 bytes for version 9.18.4, hinting at minor code or asset changes. The fileCount remains consistent at 390, suggesting that the number of files within the package didn't change between these releases.
For developers considering using highlight.js, both versions offer robust syntax highlighting capabilities. The packages share the same dependencies and devDependencies, including tools like rollup for bundling, mocha for testing, and js-beautify for code formatting. The library is licensed under the BSD-3-Clause license, offering flexibility in its usage. The subtle differences between these two versions likely involve bug fixes, minor feature enhancements, or updated language definitions. Reviewing the detailed changelog or commit history on the highlight.js GitHub repository would provide more specific insight into the exact changes implemented in version 9.18.5. Choosing the latest version is generally recommended to benefit from the most up-to-date improvements and fixes.
All the vulnerabilities related to the version 9.18.5 of the package
ReDOS vulnerabities: multiple grammars
The Regular expression Denial of Service (ReDoS) is a Denial of Service attack, that exploits the fact that most Regular Expression implementations may reach extreme situations that cause them to work very slowly (exponentially related to input size). An attacker can then cause a program using a Regular Expression to enter these extreme situations and then hang for a very long time.
If are you are using Highlight.js to highlight user-provided data you are possibly vulnerable. On the client-side (in a browser or Electron environment) risks could include lengthy freezes or crashes... On the server-side infinite freezes could occur... effectively preventing users from accessing your app or service (ie, Denial of Service).
This is an issue with grammars shipped with the parser (and potentially 3rd party grammars also), not the parser itself. If you are using Highlight.js with any of the following grammars you are vulnerable. If you are using highlightAuto to detect the language (and have any of these grammars registered) you are vulnerable. Exponential grammars (C, Perl, JavaScript) are auto-registered when using the common grammar subset/library require('highlight.js/lib/common') as of 10.4.0 - see https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.4.0/build/highlight.js
All versions prior to 10.4.1 are vulnerable, including version 9.18.5.
Grammars with exponential backtracking issues:
And of course any aliases of those languages have the same issue. ie: hpp is no safer than cpp.
Grammars with polynomial backtracking issues:
And again: any aliases of those languages have the same issue. ie: ruby and rb share the same ruby issues.
If you have any questions or comments about this advisory:
