CVE-2021-43783

Description

### Impact A malicious actor with write access to a registered scaffolder template is able to manipulate the template in a way that writes files to arbitrary paths on the scaffolder-backend host instance. This vulnerability can in some situation also be exploited through user input when executing a template, meaning you do not need write access to the templates. This method will not allow the attacker to control the contents of the injected file however, unless the template is also crafted in a specific way that gives control of the file contents. ### Patches This vulnerability is fixed in version `0.15.14` of the `@backstage/plugin-scaffolder-backend`. ### Workarounds This attack is mitigated by restricting access and requiring reviews when registering or modifying scaffolder templates. ### For more information If you have any questions or comments about this advisory: * Open an issue in the [Backstage repository](https://github.com/backstage/backstage) * Visit our chat, linked to in [Backstage README](https://github.com/backstage/backstage)

How to fix CVE-2021-43783

To remediate CVE-2021-43783, upgrade the affected package to a fixed version below.

• —upgrade to 0.15.14 or later

Is CVE-2021-43783 being exploited?

Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.

Affected packages (1)

• from 0, < 0.15.14

CVSS scores

References (4)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-43783
• PATCHgithub.com/backstage/backstage
• WEBgithub.com/backstage/backstage/commit/f9352ab606367cd9efc6ff048915c70ed3013b7f
• WEBgithub.com/backstage/backstage/security/advisories/GHSA-mg3m-f475-28hv