CVE-2021-41238
Vulnérabilité élevée dans Hangfire (HangfireIO)
Description
Hangfire is an open source system to perform background job processing in a .NET or .NET Core applications. No Windows Service or separate process required. Dashboard UI in Hangfire.Core uses authorization filters to protect it from showing sensitive data to unauthorized users. By default when no custom authorization filters specified, `LocalRequestsOnlyAuthorizationFilter` filter is being used to allow only local requests and prohibit all the remote requests to provide sensible, protected by default settings. However due to the recent changes, in version 1.7.25 no authorization filters are used by default, allowing remote requests to succeed. If you are using `UseHangfireDashboard` method with default `DashboardOptions.Authorization` property value, then your installation is impacted. If any other authorization filter is specified in the `DashboardOptions.Authorization` property, the you are not impacted. Patched versions (1.7.26) are available both on Nuget.org and as a tagged release on the github repo. Default authorization rules now prohibit remote requests by default again by including the `LocalRequestsOnlyAuthorizationFilter` filter to the default settings. Please upgrade to the newest version in order to mitigate the issue. For users who are unable to upgrade it is possible to mitigate the issue by using the `LocalRequestsOnlyAuthorizationFilter` explicitly when configuring the Dashboard UI.
Gravité et risque d'exploitation
CVE-2021-41238 obtient un score CVSS de 8.6/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.96 %, ce qui la place devant 60.9 % des CVE référencées.
Que faire ?
- Vérifiez si Hangfire (versions = 1.7.25) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.