🛡️ CVE-2021-43783 — plugin-scaffolder-backend

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-22 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Path Traversal in @backstage/plugin-scaffolder-backend

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 this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality none, integrity high, availability low.

Weakness class

CVE-2021-43783 is classified as CWE-22: Path Traversal. A file path built from user input is not confined to the intended directory, letting an attacker reach files elsewhere on the filesystem.

Affected software

CVE-2021-43783 is recorded against 1 package.

  • @backstage/plugin-scaffolder-backend

Timeline and source

Published on 1 December 2021 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L
CWE CWE-22
Public Exploit ✅ No
Source OSV
Published 2021-12-01
Updated 2026-08-12
Modified 2026-07-08
Fix URL N/A

Affected Packages

Software From version Fixed in
@backstage/plugin-scaffolder-backend — —

Similar Threats

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