All the vulnerabilities related to the version 4.4.2 of the package
Regular Expression Denial of Service (ReDoS) in micromatch
The NPM package micromatch
prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces()
in index.js
because the pattern .*
will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Uncontrolled resource consumption in braces
The NPM package braces
fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js,
if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
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:
Uncontrolled Resource Consumption in markdown-it
Special patterns with length > 50K chars can slow down parser significantly.
const md = require('markdown-it')();
md.render(`x ${' '.repeat(150000)} x \nx`);
Upgrade to v12.3.2+
No.
Fix + test sample: https://github.com/markdown-it/markdown-it/commit/ffc49ab46b5b751cd2be0aabb146f2ef84986101
yargs-parser Vulnerable to Prototype Pollution
Affected versions of yargs-parser
are vulnerable to prototype pollution. Arguments are not properly sanitized, allowing an attacker to modify the prototype of Object
, causing the addition or modification of an existing property that will exist on all objects.
Parsing the argument --foo.__proto__.bar baz'
adds a bar
property with value baz
to all objects. This is only exploitable if attackers have control over the arguments being passed to yargs-parser
.
Upgrade to versions 13.1.2, 15.0.1, 18.1.1 or later.