Quick answers
- Is This vulnerability exploited in the wild?
- No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
- How severe is This vulnerability?
- Informational severity, published 4 September 2020.
- Which products and versions are affected?
- handlebars (npm) SEMVER:introduced=0,fixed=3.0.8.
- Is there a fix for This vulnerability?
- Yes. handlebars (npm): upgrade to 3.0.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is This vulnerability attacked?
- It is attacked over the network, in a software library.
- Am I affected?
- Check whether you run handlebars (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- handlebars (npm): upgrade to 3.0.8 or later
npm install handlebars@3.0.8
Technical details
The vulnerability is an arbitrary code execution flaw in Handlebars' lookup helper, which failed to properly validate user-supplied templates. An incomplete fix for a prior issue left the helper susceptible to template injection attacks. An attacker could submit a crafted template that executes arbitrary JavaScript code. The attack vector depends on deployment: server-side processing enables code execution with server privileges; client-side rendering constitutes a cross-site scripting (XSS) vector. No authentication is required if the application accepts untrusted template input. Patches are available in versions 3.0.8, 4.5.3, and later.
Affected products
- Handlebars Handlebars prior to 3.0.8 or 4.0.0 prior to 4.5.3
Timeline
- 2020-09-04: disclosed