CVE-2021-29455 json
Missing validation of JWT signature in `grassrootza/grassroot-platform`
published 2021-04-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-16069
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 58%
- public exploits
- 0
- none known
Summary
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).
Patch / fix
Exploit prediction
0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
Affected products
- grassrootza grassroot-platform
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/grassrootza/grassroot-platform/commit/a2e6e885f8183a066d938cf909fd813a7af7d67f
patch, third-party-advisory
-
github.com
/grassrootza/grassroot-platform/security/advisories/GHSA-f65w-6xw8-6734
third-party-advisory
-
github.com
/grassrootza/grassroot-platform/
product, third-party-advisory
Sources
- CVE List CVE-2021-29455
- NVD CVE-2021-29455
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