simple-markdown@0.4.1 vulnerabilities

simple-markdown is a markdown-like parser designed for simplicity and extensibility.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) due to certain patterns which will exhibit increased complexity, therefore leading to increased parsing duration.

Upgrade simple-markdown to version 0.6.1 or higher.

simple-markdown is a markdown-like parser designed for simplicity and extensibility.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) such that spaces will be parsed as part of the \s*s or as part of the [\S\s]*, which leads to catastrophic backtracking in the case of a string with many spaces.

Upgrade simple-markdown to version 0.5.2 or higher.

simple-markdown is a markdown-like parser designed for simplicity and extensibility.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). Parsing of complex quadratic documents with may cause a slowdown of 7174ms seconds due to parsing, and could result in Denial of Service.

PoC

<script src="simple-markdown.min.js"></script>
<script>
var str = "<".repeat(2000)+":/".repeat(1500);
var t1 = performance.now();
SimpleMarkdown.defaultInlineParse(str);
var t2 = performance.now();
document.write(str.length+" bytes, "+(t2-t1)+"ms");
</script>

Upgrade simple-markdown to version 0.6.1 or higher.

simple-markdown is a markdown-like parser designed for simplicity and extensibility.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via inline code blocks.

Upgrade simple-markdown to version 0.5.2 or higher.

simple-markdown is a markdown-like parser designed for simplicity and extensibility.

Affected versions of this package are vulnerable to Cross-site Scripting (XSS) through the data of a vbscript link when base64 encoded.

POC

var SimpleMarkdown = require("simple-markdown");
var mdOutput = SimpleMarkdown.defaultHtmlOutput;
var implicitParse = SimpleMarkdown.defaultImplicitParse;
var syntaxTree = implicitParse(
  "Test payload - [link](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4=)"
);
var parsed_payload = mdOutput(syntaxTree);

document.getElementById("app").innerHTML = parsed_payload;

Upgrade simple-markdown to version 0.4.4 or higher.