CVE-2021-43783Path Traversal in @backstage/plugin-scaffolder-backend
- 8.5HighCVSS base score
- 1.2%Exploitation in 30 daysEPSS · top 30% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
@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.
Timeline
ID reserved
By GitHub_M
- 13 days later
· 13 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L |
| NVDNVD · Undergoing Analysis | 3.1 | High8.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L |
- EPSS (exploitation in 30 days)
- 1.2% · top 30% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm@backstage/plugin-scaffolder-backendGHSA-mg3m-f475-28hv (opens in a new tab)
References
References2
- https://github.com/backstage/backstage/security/advisories/GHSA-mg3m-f475-28hv (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/backstage/backstage/commit/f9352ab606367cd9efc6ff048915c70ed3013b7f (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-2554 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-mg3m-f475-28hv (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-43783)Record last updated .