Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 until 4.7.10, Handlebars.precompile() uses quotedString() in lib/handlebars/compiler/code-gen.js to emit static template text into generated JavaScript without escaping sequences that terminate an enclosing HTML script element. When an application precompiles attacker-controlled template text and embeds the generated source directly in an inline script element, a closing script delimiter can end the element and cause following attacker-controlled markup to be parsed and executed.
Ordinary server-side rendering and precompiled templates served as external JavaScript files are not affected. This issue is fixed in version 4.7.10.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/handlebars-lang/handlebars.js/commit/609d1b11c833c9a3e00f56f…
security-advisories@github.com
https://github.com/handlebars-lang/handlebars.js/pull/2185
security-advisories@github.com
https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10
security-advisories@github.com
https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xw65-…
security-advisories@github.com