CVE-2021-21337

Name: CVE-2021-21337
Creator: NVD / NIST
Published: 2021-03-08T21:15:16.807+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 8.44%

Last modified Jun 17, 2026

CVE-2021-21337 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Products.PluggableAuthService is a pluggable Zope authentication and authorization framework. In Products.PluggableAuthService before version 2.6.0 there is an open redirect vulnerability. EPSS estimates a 8.44% chance of exploitation in the next 30 days.

Description

Products.PluggableAuthService is a pluggable Zope authentication and authorization framework. In Products.PluggableAuthService before version 2.6.0 there is an open redirect vulnerability. A maliciously crafted link to the login form and login functionality could redirect the browser to a different website. The problem has been fixed in version 2.6.1. Depending on how you have installed Products.PluggableAuthService, you should change the buildout version pin to `2.6.1` and re-run the buildout, or if you used `pip` simply do `pip install "Products.PluggableAuthService>=2.6.1".

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

8.44%

94.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Zope	Products.Pluggableauthservice	< 2.6.1

References

http://packetstormsecurity.com/files/162911/Products.PluggableAuthService-2.6.0-Open-Redirect.htmlExploit, Third Party Advisory, VDB Entry
https://github.com/zopefoundation/Products.PluggableAuthService/commit/7eead067898852ebd3e0f143bc51295928528dfaPatch, Third Party Advisory
https://github.com/zopefoundation/Products.PluggableAuthService/security/advisories/GHSA-p44j-xrqg-4xrrThird Party Advisory
https://pypi.org/project/Products.PluggableAuthService/Product, Third Party Advisory
http://packetstormsecurity.com/files/162911/Products.PluggableAuthService-2.6.0-Open-Redirect.htmlExploit, Third Party Advisory, VDB Entry
https://github.com/zopefoundation/Products.PluggableAuthService/commit/7eead067898852ebd3e0f143bc51295928528dfaPatch, Third Party Advisory
https://github.com/zopefoundation/Products.PluggableAuthService/security/advisories/GHSA-p44j-xrqg-4xrrThird Party Advisory
https://pypi.org/project/Products.PluggableAuthService/Product, Third Party Advisory

Timeline

Published: Mar 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21337?

How severe is CVE-2021-21337?

CVE-2021-21337 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 8.44% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21337?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21337?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST