CVE-2021-21276
CVSS V2 Medium 6.4
CVSS V3 Critical 9.3
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.
Overview
- CVE ID
- CVE-2021-21276
- Assigner
- security-advisories@github.com
- Vulnerability Status
- Modified
- Published Version
- 2021-02-01T15:15:13
- Last Modified Date
- 2023-04-06T17:15:09
Weakness Enumerations
CPE Configuration (Product)
| CPE | Vulnerable | Operator | Version Start | Version End |
|---|---|---|---|---|
| cpe:2.3:a:polrproject:polr:*:*:*:*:*:*:*:* | 1 | OR | 2.3.0 |
CVSS Version 2
- Version
- 2.0
- Vector String
- AV:N/AC:L/Au:N/C:P/I:P/A:N
- Access Vector
- NETWORK
- Access Compatibility
- LOW
- Authentication
- NONE
- Confidentiality Impact
- PARTIAL
- Integrity Impact
- PARTIAL
- Availability Impact
- NONE
- Base Score
- 6.4
- Severity
- MEDIUM
- Exploitability Score
- 10
- Impact Score
- 4.9
CVSS Version 3
- Version
- 3.1
- Vector String
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
- Attack Vector
- NETWORK
- Attack Compatibility
- LOW
- Privileges Required
- NONE
- User Interaction
- NONE
- Scope
- CHANGED
- Confidentiality Impact
- HIGH
- Availability Impact
- NONE
- Base Score
- 9.3
- Base Severity
- CRITICAL
- Exploitability Score
- 3.9
- Impact Score
- 4.7
References
| Reference URL | Reference Tags |
|---|---|
| http://packetstormsecurity.com/files/171743/POLR-URL-2.3.0-Shortener-Admin-Takeover.html | |
| https://github.com/cydrobolt/polr/commit/b1981709908caf6069b4a29dad3b6739c322c675 | Patch Third Party Advisory |
| https://github.com/cydrobolt/polr/releases/tag/2.3.0 | Release Notes Third Party Advisory |
| https://github.com/cydrobolt/polr/security/advisories/GHSA-vg6w-8w9v-xxqc | Third Party Advisory |
Sources
| Source Name | Source URL |
|---|---|
| NIST | https://nvd.nist.gov/vuln/detail/CVE-2021-21276 |
| MITRE | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21276 |
History
| Created | Old Value | New Value | Data Type | Notes |
|---|---|---|---|---|
| 2022-05-10 07:24:03 | Added to TrackCVE | |||
| 2022-12-05 21:09:41 | 2021-02-01T15:15Z | 2021-02-01T15:15:13 | CVE Published Date | updated |
| 2022-12-05 21:09:41 | 2022-07-11T18:59:04 | CVE Modified Date | updated | |
| 2022-12-05 21:09:41 | Analyzed | Vulnerability Status | updated | |
| 2023-04-06 20:09:30 | 2023-04-06T17:15:09 | CVE Modified Date | updated | |
| 2023-04-06 20:09:30 | Analyzed | Modified | Vulnerability Status | updated |
| 2023-04-06 20:09:31 | Weakness Enumeration | update | ||
| 2023-04-06 20:09:31 | References | updated |