CVE-2021-21276
Polr Access Bypass Vulnerability (Path-Traversing)
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.
INFO
Published Date :
Feb. 1, 2021, 3:15 p.m.
Last Modified :
Nov. 21, 2024, 5:47 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
4.7
Exploitability Score :
3.9
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-21276.
| URL | Resource |
|---|---|
| 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 |
| 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 |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-21276 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-21276 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/171743/POLR-URL-2.3.0-Shortener-Admin-Takeover.html Added Reference https://github.com/cydrobolt/polr/commit/b1981709908caf6069b4a29dad3b6739c322c675 Added Reference https://github.com/cydrobolt/polr/releases/tag/2.3.0 Added Reference https://github.com/cydrobolt/polr/security/advisories/GHSA-vg6w-8w9v-xxqc -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Apr. 06, 2023
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/171743/POLR-URL-2.3.0-Shortener-Admin-Takeover.html [No Types Assigned] -
Reanalysis by [email protected]
Jul. 11, 2022
Action Type Old Value New Value Added CWE NIST NVD-CWE-Other -
Initial Analysis by [email protected]
Feb. 08, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:N) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N Changed Reference Type https://github.com/cydrobolt/polr/commit/b1981709908caf6069b4a29dad3b6739c322c675 No Types Assigned https://github.com/cydrobolt/polr/commit/b1981709908caf6069b4a29dad3b6739c322c675 Patch, Third Party Advisory Changed Reference Type https://github.com/cydrobolt/polr/releases/tag/2.3.0 No Types Assigned https://github.com/cydrobolt/polr/releases/tag/2.3.0 Release Notes, Third Party Advisory Changed Reference Type https://github.com/cydrobolt/polr/security/advisories/GHSA-vg6w-8w9v-xxqc No Types Assigned https://github.com/cydrobolt/polr/security/advisories/GHSA-vg6w-8w9v-xxqc Third Party Advisory Added CPE Configuration OR *cpe:2.3:a:polrproject:polr:*:*:*:*:*:*:*:* versions up to (excluding) 2.3.0
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-21276 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-21276
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
16.15 }} -6.32%
score
0.94243
percentile