Handlebars version 4.2.1 is a minor release following the 4.2.0 version of this popular templating engine, primarily focused on refinements and bug fixes rather than introducing groundbreaking new features. Both versions share the same core dependencies, including neo-async, optimist, source-map, and uglify-js, ensuring a consistent foundation for developers. The development dependencies also remain identical, indicating a shared tooling and testing environment. Key tools like grunt, webpack, and various testing frameworks such as mocha highlight the commitment to quality and maintainability.
The relatively small difference in unpackedSize in the dist object (2404301 vs 2519270) suggests the changes between the versions are likely concentrated in specific areas of the codebase, impacting efficiency or resolving issues within the existing functionalities. The releaseDate indicates a roughly two-week gap between the releases, suggesting the newer version is a quick response possibly to address issues identified in the previous one.
For developers, upgrading from 4.2.0 to 4.2.1 promises a more stable and refined experience with the same familiar API and capabilities. The absence of major dependency updates ensures backward compatibility and minimizes the risk of introducing breaking changes into existing projects. While specific bug fixes and performance enhancements aren't detailed in this summary, they would typically center around template parsing, rendering performance, or handling edge cases in the Handlebars language. Therefore, users prioritizing stability and incremental improvements should consider adopting version 4.2.1.
All the vulnerabilities related to the version 4.2.1 of the package
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.
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.
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.
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).
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
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.
Prototype Pollution in minimist
Affected versions of minimist 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 --__proto__.y=Polluted adds a y property with value Polluted to all objects. The argument --__proto__=Polluted raises and uncaught error and crashes the application.
This is exploitable if attackers have control over the arguments being passed to minimist.
Upgrade to versions 0.2.1, 1.2.3 or later.
Prototype Pollution in minimist
Minimist prior to 1.2.6 and 0.2.4 is vulnerable to Prototype Pollution via file index.js, function setKey() (lines 69-95).