Backstage has a Possible Symlink Path Traversal in Scaffolder Actions
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 0.12.2, 0.13.2, 0.14.1, 2.2.2, 3.0.2, and 3 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 proof of concept on GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
Backstage is an open framework for building developer portals. Multiple Scaffolder actions and archive extraction utilities were vulnerable to symlink-based path traversal attacks. An attacker with access to create and execute Scaffolder templates could exploit symlinks to read arbitrary files via the `debug:log` action by creating a symlink pointing to sensitive files (e.g., `/etc/passwd`, configuration files, secrets); delete arbitrary files via the `fs:delete` action by creating symlinks pointing outside the workspace, and write files outside the workspace via archive extraction (tar/zip) containing malicious symlinks. This affects any Backstage deployment where users can create or execute Scaffolder templates. This vulnerability is fixed in `@backstage/backend-defaults` versions 0.12.2, 0.13.2, 0.14.1, and 0.15.0; `@backstage/plugin-scaffolder-backend` versions 2.2.2, 3.0.2, and 3.1.1; and `@backstage/plugin-scaffolder-node` versions 0.11.2 and 0.12.3. Users should upgrade to these versions or later. Some workarounds are available. Follow the recommendation in the Backstage Threat Model to limit access to creating and updating templates, restrict who can create and execute Scaffolder templates using the permissions framework, audit existing templates for symlink usage, and/or run Backstage in a containerized environment with limited filesystem access.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- backstage backstage
@backstage/backend-defaults < 0.12.2, @backstage/plugin-scaffolder-backend < 2.2.2, @backstage/plugin-scaffolder-node < 0.11.2
- @backstage/backend-defaultsnpm
fixed in 0.12.2
- @backstage/backend-defaultsnpm
From 0.13.0 · fixed in 0.13.2
- @backstage/backend-defaultsnpm
From 0.14.0 · fixed in 0.14.1
- @backstage/plugin-scaffolder-backendnpm
fixed in 2.2.2
- @backstage/plugin-scaffolder-backendnpm
From 3.0.0 · fixed in 3.0.2
- @backstage/plugin-scaffolder-backendnpm
From 3.1.0 · fixed in 3.1.1
- @backstage/plugin-scaffolder-nodenpm
fixed in 0.11.2
- @backstage/plugin-scaffolder-nodenpm
From 0.12.0 · fixed in 0.12.3