CVE-2021-21276

 

Published at: - 01-02-2021 04:15

Last modified: - 11-07-2022 08:59

Total changes: - 3

Description

Polr is an open source URL shortener. in Polr before version 2.3.0, a vulnerability in the setup process allows attackers to gain admin access to site instances, even if they do not possess an existing account. This vulnerability exists regardless of users' settings. If an attacker crafts a request with specific cookie headers to the /setup/finish endpoint, they may be able to obtain admin privileges on the instance. This is caused by a loose comparison (==) in SetupController that is susceptible to attack. The project has been patched to ensure that a strict comparison (===) is used to verify the setup key, and that /setup/finish verifies that no users table exists before performing any migrations or provisioning any new accounts. This is fixed in version 2.3.0. Users can patch this vulnerability without upgrading by adding abort(404) to the very first line of finishSetup in SetupController.php.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N

 

Verification logic

 

Reference

• https://github.com/cydrobolt/polr/commit/b1981709908caf6069b4a29dad3b6739c322c675
• https://github.com/cydrobolt/polr/security/advisories/GHSA-vg6w-8w9v-xxqc
• https://github.com/cydrobolt/polr/releases/tag/2.3.0

 

Keywords

NVD

 

CVE-2021-21276

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures