RCE in Express Handlebars Project
CVE-2021-32817
express-hbs is an Express handlebars template engine. express-hbs mixes pure template data with engine configuration options through the Express render API. More specifically, the layout parameter may trigger file disclosure vulnerabilities in downstream applications. This potential vulnerability is somewhat restricted in that only files with existing extentions (i.e. file.extension) can be included, files that lack an extension will have .hbs appended to them. For complete details refer to the referenced GHSL-2021-019 report. Notes in documentation have been added to help users of express-hbs avoid this potential information exposure vulnerability.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.013 (68.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 68.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000
Affected products
- Express Handlebars Project
- Tryghost Express-Hbs — versions < 2.4.0
Weakness classification (CWE)
References
- securitylab.github.com/advisories/GHSL-2021-019-express-hbs/ (Exploit, Patch, Third Party Advisory)
- www.npmjs.com/package/express-hbs (Product)
- github.com/TryGhost/express-hbs (Third Party Advisory, Release Notes)
- github.com/TryGhost/express-hbs/commit/ff6fad6e357699412d4e916273314e5e7af1500e (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32817?
- CVE-2021-32817 is a medium-severity vulnerability in Express Handlebars Project, classified under Information Disclosure. CVSS score: 5.4/10. Published 2021-05-14.
- How severe is CVE-2021-32817?
- Medium severity. CVSS v3 base score is 5.4 out of 10.