CVE-2021-43783
mediumpriority · track · 34EPSS 0.012 · 69 %ileEUUSEPSS · scored 2026-10-27
@backstage/plugin-scaffolder-backend is the backend for the default Backstage software templates. In affected versions 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. This vulnerability is fixed in version `0.15.14` of the `@backstage/plugin-scaffolder-backend`. This attack is mitigated by restricting access and requiring reviews when registering or modifying scaffolder templates.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.5–8.5
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
- npm @backstage/plugin-scaffolder-backend< 0.15.14osvUSpkg:npm/%40backstage/plugin-scaffolder-backend
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-mg3m-f475-28hvPath Traversal in @backstage/plugin-scaffolder-backend2021-12-01ghsa · osvUS
### 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)
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://github.com/backstage/backstage/commit/f9352ab606367cd9efc6ff048915c70ed3013b7fcnnvd
- https://github.com/backstage/backstage/security/advisories/GHSA-mg3m-f475-28hvcnnvd
- https://github.com/backstage/backstage/commit/f9352ab606367cd9efc6ff048915c70ed3013b7fenisa_euvd
- https://github.com/backstage/backstage/security/advisories/GHSA-mg3m-f475-28hvenisa_euvd
- https://github.com/backstage/backstage/commit/f9352ab606367cd9efc6ff048915c70ed3013b7fPatchThird Party Advisorynvd
- https://github.com/backstage/backstage/security/advisories/GHSA-mg3m-f475-28hvThird Party Advisorynvd
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