The Backstage Scaffolder plugin Houses types and utilities for building scaffolder-related modules. A vulnerability is identified in Backstage Scaffolder template functionality where Server-Side Template Injection (SSTI) can be exploited to perform Git config injection. The vulnerability allows an attacker to capture privileged git tokens used by the Backstage Scaffolder plugin. With these tokens, unauthorized access to sensitive resources in git can be achieved. The impact is considered medium severity as the Backstage Threat Model recommends restricting access to adding and editing templates in the Backstage Catalog plugin. The issue has been resolved in versions `v0.4.12`, `v0.5.1` and `v0.6.1` of the `@backstage/plugin-scaffolder-node` package. Users are encouraged to upgrade to this version to mitigate the vulnerability. Users are advised to upgrade. Users unable to upgrade may ensure that templates do not change git config.

Backstage is an open framework for building developer portals. Configuration supplied through APP_CONFIG_* environment variables, for example APP_CONFIG_backend_listen_port=7007, where unexpectedly ignoring the visibility defined in configuration schema. This occurred even if the configuration schema specified that they should have backend or secret visibility. This was an intended feature of the APP_CONFIG_* way of supplying configuration, but now clearly goes against the expected behavior of the configuration system. This behavior leads to a risk of potentially exposing sensitive configuration details intended to remain private or restricted to backend processes. The issue has been resolved in version 0.3.75 of the @backstage/plugin-app-backend package. As a temporary measure, avoid supplying secrets using the APP_CONFIG_ configuration pattern. Consider alternative methods for setting secrets, such as the environment substitution available for Backstage configuration.