CVE-2024-45399: Indico has a Cross-Site-Scripting during account creation

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-09-04 · updated 2026-06-17
Weakness: CWE-79

Description

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. In Indico prior to version 3.3.4, corresponding to Flask-Multipass prior to version 0.5.5, there is a Cross-Site-Scripting vulnerability during account creation when redirecting to the `next` URL. Exploitation requires initiating the account creation process with a maliciously crafted link, and then finalizing the signup process. Because of this, it can only target newly created (and thus unprivileged) Indico users. Indico 3.3.4 upgrades the dependency on Flask-Multipass to version 0.5.5, which fixes the issue. Those who build the Indico package themselves and cannot upgrade can update the `flask-multipass` dependency to `>=0.5.5` which fixes the vulnerability. Otherwise one could configure one's web server to disallow requests containing a query string with a `next` parameter that starts with `javascript:`.

Affected products

indico: before 3.3.4 — fixed in 3.3.4

How to fix

Upgrade to a fixed version: indico 3.3.4. Check the vendor advisory for mitigations.

References

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