Description
Handlebars provides the power necessary to let users build semantic templates. From 3.0.0 until 4.7.10, Handlebars lookupProperty returns Function.prototype.constructor before applying the prototype-access deny list because constructor is an own property of Function.prototype. When an attacker can render a controlled template with allowProtoMethodsByDefault enabled and an accessible function in the template context, the template can traverse from that function through its prototype to Function.prototype and then obtain the Function constructor through the own-property bypass. This permits attacker-controlled JavaScript to execute with the server application's privileges. This issue is fixed in version 4.7.10.
CVSS breakdown
CVSS 4.0
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality (Vulnerable System)
High
Integrity (Vulnerable System)
High
Availability (Vulnerable System)
High
Confidentiality (Subsequent System)
None
Integrity (Subsequent System)
None
Availability (Subsequent System)
None
Affected products
- handlebars-lang / handlebars.js>= 4.0.0, < 4.7.10 – >= 4.0.0, < 4.7.10
- handlebars-lang / handlebars.js>= 3.0.0, < 4.7.10 – >= 3.0.0, < 4.7.10
References
- VENDOR_ADVISORYhttps://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-p8wg-vrv2-v86f
- PATCHhttps://github.com/handlebars-lang/handlebars.js/pull/2185
- PATCHhttps://github.com/handlebars-lang/handlebars.js/commit/ceec388abe1d1aac8f6369860d5f390fa71ef4fa
- PATCHhttps://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10
Updated 37m ago · 8 sources