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GHSA-824x-88xg-cwrv

Redaxo has Path Traversal in Backup Addon Leading to Arbitrary File Read

Also known asCVE-2026-21857
Published
Jan 5, 2026
Updated
Feb 3, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk38th percentile+0.46%
0.00%0.33%0.66%0.99%0.1%0.5%Feb 26May 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected
🐘redaxo/source

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Authenticated users with backup permissions can read arbitrary files within the webroot via path traversal in the Backup addon's file export functionality. <img width="664" height="899" alt="image" src="https://github.com/user-attachments/assets/fd1ca69e-b275-4daf-9a62-621cde6525f5" /> <img width="2358" height="445" alt="image" src="https://github.com/user-attachments/assets/fad81152-9e1b-413e-9823-09540a23e2fb" />

Details

The Backup addon does not validate the EXPDIR POST parameter against the UI-generated allowlist of permitted directories.
An attacker can supply relative paths containing ../ sequences (or even absolute paths inside the document root) to include any readable file in the generated .tar.gz archive.

Vulnerable code:

  • redaxo/src/addons/backup/pages/export.php (lines 72-76) – directly uses $_POST['EXPDIR']
  • redaxo/src/addons/backup/lib/backup.php (lines ~413 & ~427) – concatenates unsanitized user input with base path

This allows disclosure of sensitive files such as:

  • redaxo/data/core/config.yml → database credentials + password hashes of all backend users
  • .env, custom configuration files, logs, uploaded malicious files, etc.

Affected versions

≤ 5.20.1 (confirmed working)

Patched versions

None (as of 2025-12-09)

PoC – Extracting database credentials and password hashes

  1. Log in as any user with Backup permission
  2. Go to Backup → Export → Files
<img width="1240" height="960" alt="image" src="https://github.com/user-attachments/assets/bc05ba18-9664-4be2-b637-4fec3a0f409a" />
  1. Intercept the request with Burp Suite
<img width="2184" height="478" alt="image" src="https://github.com/user-attachments/assets/9fa754a1-2cd0-4d3d-a5cc-cfa34c8a1718" />
  1. Change one EXPDIR[] value to ../../../../var/www/html/redaxo/data/core
<img width="978" height="591" alt="image" src="https://github.com/user-attachments/assets/d15f5c7f-b72c-44cc-9be2-da8d3f26f124" />
  1. Send request → download archive

    <img width="423" height="131" alt="image" src="https://github.com/user-attachments/assets/db8a8bda-cdaf-4dea-812f-1e312da908e2" />
  2. Extract and open data/core/config.yml

    <img width="859" height="281" alt="image" src="https://github.com/user-attachments/assets/c8112ce1-5a1d-435f-953b-7eb4e711e042" />

Result: plaintext database password <img width="2534" height="1198" alt="image" src="https://github.com/user-attachments/assets/218ae917-868a-437e-98b0-6471b82c0b10" />

Impact

Full compromise of the REDAXO installation:

  • Database takeover
  • Password hash extraction → offline cracking → admin access
  • When combined with other vulnerabilities → RCE

CVSS 4.0 vector & score below.

Credits

Discovered by: Łukasz Rybak

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistredaxo/sourceall versions5.20.2

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for redaxo/source. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update redaxo/source to 5.20.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-824x-88xg-cwrv is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-824x-88xg-cwrv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-824x-88xg-cwrv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Authenticated users with backup permissions can read arbitrary files within the webroot via path traversal in the Backup addon's file export functionality. <img width="664" height="899" alt="image" src="https://github.com/user-attachments/assets/fd1ca69e-b275-4daf-9a62-621cde6525f5" /> <img width="2358" height="445" alt="image" src="https://github.com/user-attachments/assets/fad81152-9e1b-413e-9823-09540a23e2fb" /> ### Details The Backup addon does not validate the `EXPDIR` POST parameter against the UI-generated allowlist of permitted directories. An attacker can supply relati
O3 Security · Impact-Aware SCA

Is GHSA-824x-88xg-cwrv in your dependencies?

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