CVE-2025-53640

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Starting in version 2.2 and prior to version 3.3.7, an endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk. Version 3.3.7 fixes the issue. Owners of instances that allow everyone to create a user account, who wish to truly restrict access to these user details, should consider restricting user search to managers. As a workaround, it is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Starting in version 2.2 and prior to version 3.3.7, an endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk. Version 3.3.7 fixes the issue. Owners of instances that allow everyone to create a user account, who wish to truly restrict access to these user details, should consider restricting user search to managers. As a workaround, it is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

Impact

An endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk.

[!TIP] If your instance allows everyone to create a user account, and you wish to truly restrict access to these user details, consider restricting user search to managers. You can find details on the newly introduced indico.conf setting ALLOW_PUBLIC_USER_SEARCH in our documentation.

Patches

You should to update to Indico 3.3.7 as soon as possible. See the docs for instructions on how to update.

Workarounds

It is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

For more information

If you have any questions or comments about this advisory:

• Open a thread in our forum
• Email us privately at [email protected]

Credits

This vulnerability was identified during a security assessment conducted as part of the Red Team Residency Program at RNP (Rede Nacional de Ensino e Pesquisa). The research and testing were performed by a security researcher working under RNP’s authorization and coordination. Special acknowledgment goes to the RNP Security Team, which provided the infrastructure, methodology, and ethical oversight for this work.

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Starting in version 2.2 and prior to version 3.3.7, an endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk. Version 3.3.7 fixes the issue. Owners of instances that allow everyone to create a user account, who wish to truly restrict access to these user details, should consider restricting user search to managers. As a workaround, it is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Starting in version 2.2 and prior to version 3.3.7, an endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk. Version 3.3.7 fixes the issue. Owners of instances that allow everyone to create a user account, who wish to truly restrict access to these user details, should consider restricting user search to managers. As a workaround, it is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

Impact

An endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk.

[!TIP] If your instance allows everyone to create a user account, and you wish to truly restrict access to these user details, consider restricting user search to managers. You can find details on the newly introduced indico.conf setting ALLOW_PUBLIC_USER_SEARCH in our documentation.

Patches

You should to update to Indico 3.3.7 as soon as possible. See the docs for instructions on how to update.

Workarounds

It is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

For more information

If you have any questions or comments about this advisory:

• Open a thread in our forum
• Email us privately at [email protected]

Credits

This vulnerability was identified during a security assessment conducted as part of the Red Team Residency Program at RNP (Rede Nacional de Ensino e Pesquisa). The research and testing were performed by a security researcher working under RNP’s authorization and coordination. Special acknowledgment goes to the RNP Security Team, which provided the infrastructure, methodology, and ethical oversight for this work.

Impact

An endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk.

[!TIP] If your instance allows everyone to create a user account, and you wish to truly restrict access to these user details, consider restricting user search to managers. You can find details on the newly introduced indico.conf setting ALLOW_PUBLIC_USER_SEARCH in our documentation.

Patches

You should to update to Indico 3.3.7 as soon as possible. See the docs for instructions on how to update.

Workarounds

It is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.

For more information

If you have any questions or comments about this advisory:

• Open a thread in our forum
• Email us privately at [email protected]

Credits

This vulnerability was identified during a security assessment conducted as part of the Red Team Residency Program at RNP (Rede Nacional de Ensino e Pesquisa). The research and testing were performed by a security researcher working under RNP’s authorization and coordination. Special acknowledgment goes to the RNP Security Team, which provided the infrastructure, methodology, and ethical oversight for this work.