Cyber Resilience

CVE-2021-21320

Low

Published: 02 March 2021

Published
02 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 2.6 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0018 39.3th percentile
Risk Priority 5 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21320 is a low-severity Insufficient Verification of Data Authenticity (CWE-345) vulnerability in Matrix-React-Sdk Project Matrix-React-Sdk. Its CVSS base score is 2.6 (Low).

Operationally, ranked at the 39.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

matrix-react-sdk is an npm package which is a Matrix SDK for React Javascript. In matrix-react-sdk before version 3.15.0, the user content sandbox can be abused to trick users into opening unexpected documents. The content is opened with a `blob` origin…

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that cannot access Matrix user data, so messages and secrets are not at risk. This has been fixed in version 3.15.0.

CWE(s)

Related Threats

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

Affected Assets

matrix-react-sdk project
matrix-react-sdk
≤ 3.15.0

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-345

Directly requires independent verification of matching output before adverse decisions, mitigating insufficient authenticity checks on data from external sources.

addresses: CWE-345

Use of approved PKI certificates provides verifiable data authenticity and origin for communications and artifacts.

addresses: CWE-345

Mandates provision of authenticity and integrity artifacts that enable verification of name/address resolution data.

addresses: CWE-345

Requires explicit verification of data authenticity from authoritative sources, preventing acceptance of unauthenticated resolution responses.

addresses: CWE-345

Control requires verification of data authenticity/integrity (e.g., checksums) after aggregation/packing, directly reducing exploitation of insufficient verification before transmission.

addresses: CWE-345

Time synchronization supports reliable freshness verification when checking data authenticity across systems or components.

addresses: CWE-345

Mandates verification of data authenticity for software, firmware, and information.

addresses: CWE-345

Provenance documentation and monitoring directly enables verification of authenticity for components and data throughout their history.

References