CVE-2021-29455

Name: CVE-2021-29455
Creator: NVD / NIST
Published: 2021-04-19T19:15:17.827+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.76%

Last modified Jun 17, 2026

CVE-2021-29455 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Grassroot Platform is an application to make it faster, cheaper and easier to persistently organize and mobilize people in low-income communities. Grassroot Platform before master deployment as of 2021-04-16 did not properly verify the signature of JSON Web Tokens when refreshing an existing JWT. EPSS estimates a 0.76% chance of exploitation in the next 30 days.

Description

Grassroot Platform is an application to make it faster, cheaper and easier to persistently organize and mobilize people in low-income communities. Grassroot Platform before master deployment as of 2021-04-16 did not properly verify the signature of JSON Web Tokens when refreshing an existing JWT. This allows to forge a valid JWT. The problem has been patched in version 1.3.1 by deprecating the JWT refresh function, which was an overdue deprecation regardless (the "refresh" flow is no longer used).

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.76%

50.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-347

Affected Software

Vendor	Product	Versions
Grassroot	Grassroot Platform	< 1.3.1

References

https://github.com/grassrootza/grassroot-platform/Product, Third Party Advisory
https://github.com/grassrootza/grassroot-platform/commit/a2e6e885f8183a066d938cf909fd813a7af7d67fPatch, Third Party Advisory
https://github.com/grassrootza/grassroot-platform/security/advisories/GHSA-f65w-6xw8-6734Third Party Advisory
https://github.com/grassrootza/grassroot-platform/Product, Third Party Advisory
https://github.com/grassrootza/grassroot-platform/commit/a2e6e885f8183a066d938cf909fd813a7af7d67fPatch, Third Party Advisory
https://github.com/grassrootza/grassroot-platform/security/advisories/GHSA-f65w-6xw8-6734Third Party Advisory

Timeline

Published: Apr 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29455?

How severe is CVE-2021-29455?

CVE-2021-29455 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.76% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29455?

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-2021-29455?

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

Scan your code now

Source: NVD / NIST