All the vulnerabilities related to the version 3.1.8 of the package
Arbitrary Code Execution in handlebars
Versions of handlebars prior to 3.0.8 or 4.5.2 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).
The following template can be used to demonstrate the vulnerability:
{{#with split as |a|}}
{{pop (push "alert('Vulnerable Handlebars JS');")}}
{{#with (concat (lookup join (slice 0 1)))}}
{{#each (slice 2 3)}}
{{#with (apply 0 a)}}
{{.}}
{{/with}}
{{/each}}
{{/with}}
{{/with}}
{{/with}}```
## Recommendation
Upgrade to version 3.0.8, 4.5.2 or later.
Arbitrary Code Execution in Handlebars
Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. This can be used to run arbitrary code on a server processing Handlebars templates or in a victim's browser (effectively serving as XSS).
Regular Expression Denial of Service in Handlebars
Handlebars before 4.4.5 allows Regular Expression Denial of Service (ReDoS) because of eager matching. The parser may be forced into an endless loop while processing crafted templates. This may allow attackers to exhaust system resources.
Prototype Pollution in handlebars
The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.
Remote code execution in handlebars when compiling templates
The package handlebars before 4.7.7 are vulnerable to Remote Code Execution (RCE) when selecting certain compiling options to compile templates coming from an untrusted source.
Denial of Service in handlebars
Affected versions of handlebars are vulnerable to Denial of Service. The package's parser may be forced into an endless loop while processing specially-crafted templates. This may allow attackers to exhaust system resources leading to Denial of Service.
Upgrade to version 4.4.5 or later.
Prototype Pollution in handlebars
Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to prototype pollution. It is possible to add or modify properties to the Object prototype through a malicious template. This may allow attackers to crash the application or execute Arbitrary Code in specific conditions.
Upgrade to version 3.0.8, 4.5.3 or later.
Arbitrary Code Execution in handlebars
Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It is due to an incomplete fix for a previous issue. This vulnerability can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).
Upgrade to version 3.0.8, 4.5.3 or later.
Prototype Pollution in handlebars
Versions of handlebars prior to 3.0.8 or 4.3.0 are vulnerable to Prototype Pollution leading to Remote Code Execution. Templates may alter an Objects' __proto__ and __defineGetter__ properties, which may allow an attacker to execute arbitrary code through crafted payloads.
Upgrade to version 3.0.8, 4.3.0 or later.
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:
Prototype Pollution in highlight.js
Affected versions of this package are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable.
The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector.
If your website or application does not render user provided data it should be unaffected.
Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.
Manually patch your library to create null objects for both languages and aliases:
const HLJS = function(hljs) {
// ...
var languages = Object.create(null);
var aliases = Object.create(null);
Filter the language names that users are allowed to inject into your HTML to guarantee they are valid.
If you have any questions or comments about this advisory:
Denial of Service in js-yaml
Versions of js-yaml prior to 3.13.0 are vulnerable to Denial of Service. By parsing a carefully-crafted YAML file, the node process stalls and may exhaust system resources leading to a Denial of Service.
Upgrade to version 3.13.0.
Code Injection in js-yaml
Versions of js-yaml prior to 3.13.1 are vulnerable to Code Injection. The load() function may execute arbitrary code injected through a malicious YAML file. Objects that have toString as key, JavaScript code as value and are used as explicit mapping keys allow attackers to execute the supplied code through the load() function. The safeLoad() function is unaffected.
An example payload is
{ toString: !<tag:yaml.org,2002:js/function> 'function (){return Date.now()}' } : 1
which returns the object
{
"1553107949161": 1
}
Upgrade to version 3.13.1.
js-yaml has prototype pollution in merge (<<)
In js-yaml 4.1.0, 4.0.0, and 3.14.1 and below, it's possible for an attacker to modify the prototype of the result of a parsed yaml document via prototype pollution (__proto__). All users who parse untrusted yaml documents may be impacted.
Problem is patched in js-yaml 4.1.1 and 3.14.2.
You can protect against this kind of attack on the server by using node --disable-proto=delete or deno (in Deno, pollution protection is on by default).
https://cheatsheetseries.owasp.org/cheatsheets/Prototype_Pollution_Prevention_Cheat_Sheet.html
Inefficient Regular Expression Complexity in marked
What kind of vulnerability is it?
Denial of service.
The regular expression inline.reflinkSearch may cause catastrophic backtracking against some strings.
PoC is the following.
import * as marked from 'marked';
console.log(marked.parse(`[x]: x
\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](`));
Who is impacted?
Anyone who runs untrusted markdown through marked and does not use a worker with a time limit.
Has the problem been patched?
Yes
What versions should users upgrade to?
4.0.10
Is there a way for users to fix or remediate the vulnerability without upgrading?
Do not run untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.
Are there any links users can visit to find out more?
If you have any questions or comments about this advisory:
Inefficient Regular Expression Complexity in marked
What kind of vulnerability is it?
Denial of service.
The regular expression block.def may cause catastrophic backtracking against some strings.
PoC is the following.
import * as marked from "marked";
marked.parse(`[x]:${' '.repeat(1500)}x ${' '.repeat(1500)} x`);
Who is impacted?
Anyone who runs untrusted markdown through marked and does not use a worker with a time limit.
Has the problem been patched?
Yes
What versions should users upgrade to?
4.0.10
Is there a way for users to fix or remediate the vulnerability without upgrading?
Do not run untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.
Are there any links users can visit to find out more?
If you have any questions or comments about this advisory:
Marked ReDoS due to email addresses being evaluated in quadratic time
Versions of marked from 0.3.14 until 0.6.2 are vulnerable to Regular Expression Denial of Service. Email addresses may be evaluated in quadratic time, allowing attackers to potentially crash the node process due to resource exhaustion.
Upgrade to version 0.6.2 or later.
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.