CVE-2021-39197

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2021-39197
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-09-07 18:15:00 UTC
Updated2021-09-14 18:34:00 UTC
Descriptionbetter_errors is an open source replacement for the standard Rails error page with more information rich error pages. It is also usable outside of Rails in any Rack app as Rack middleware. better_errors prior to 2.8.0 did not implement CSRF protection for its internal requests. It also did not enforce the correct "Content-Type" header for these requests, which allowed a cross-origin "simple request" to be made without CORS protection. These together left an application with better_errors enabled open to cross-origin attacks. As a developer tool, better_errors documentation strongly recommends addition only to the `development` bundle group, so this vulnerability should only affect development environments. Please ensure that your project limits better_errors to the `development` group (or the non-Rails equivalent). Starting with release 2.8.x, CSRF protection is enforced. It is recommended that you upgrade to the latest release, or minimally to "~> 2.8.3". There are no known workarounds to mitigate the risk of using older releases of better_errors.

Risk And Classification

Problem Types: CWE-352

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Better Errors Project Better Errors All All All All

References

ReferenceSourceLinkTags
Cross-Site Request Forgery vulnerability · Discussion #507 · BetterErrors/better_errors · GitHub MISC github.com
Merge pull request #474 from BetterErrors/feature/add-csrf-to-requests · BetterErrors/better_errors@8e8e796 · GitHub MISC github.com
Vulnerable to Cross-Site Request Forgery in development · Advisory · BetterErrors/better_errors · GitHub CONFIRM github.com
Add CSRF protection to internal requests by RobinDaugherty · Pull Request #474 · BetterErrors/better_errors · GitHub MISC github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report