CVE-2021-21276

Published Feb 1, 2021

Last updated 2 years ago

Overview

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.
Source
security-advisories@github.com
NVD status
Modified

Social media

Hype score
Not currently trending

Risk scores

CVSS 3.1

Type
Primary
Base score
9.3
Impact score
4.7
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Severity
CRITICAL

CVSS 2.0

Type
Primary
Base score
6.4
Impact score
4.9
Exploitability score
10
Vector string
AV:N/AC:L/Au:N/C:P/I:P/A:N

Weaknesses

security-advisories@github.com
CWE-863
nvd@nist.gov
NVD-CWE-Other

Configurations