Cyber Resilience

CVE-2021-29455

High

Published: 19 April 2021

Published
19 April 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0020 42.1th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-29455 is a high-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Grassroot Grassroot Platform. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 42.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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).

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

grassroot
grassroot platform
≤ 1.3.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-347

Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.

addresses: CWE-347

Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.

addresses: CWE-347

PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.

addresses: CWE-347

Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.

addresses: CWE-347

Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.

addresses: CWE-347

Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.

addresses: CWE-347

Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.

References