Cyber Resilience

CVE-2021-20843

Medium

Published: 24 November 2021

Published
24 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0028 52.0th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20843 is a medium-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Yamaha Rtx830 Firmware. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 48.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Cross-site script inclusion vulnerability in the Web GUI of RTX830 Rev.15.02.17 and earlier, NVR510 Rev.15.01.18 and earlier, NVR700W Rev.15.00.19 and earlier, and RTX1210 Rev.14.01.38 and earlier allows a remote authenticated attacker to alter the settings of the product via a…

more

specially crafted web page.

CWE(s)

Related Threats

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

Affected Assets

yamaha
rtx830 firmware
≤ 15.02.17
yamaha
nvr510 firmware
≤ 15.01.18
yamaha
nvr700w firmware
≤ 15.00.19
yamaha
rtx1210 firmware
≤ 14.01.38
ntt-west
biz box rtx830 firmware
≤ 15.02.17
ntt-west
biz box nvr510 firmware
≤ 15.01.18
ntt-west
biz box nvr700w firmware
≤ 15.00.19
ntt-west
biz box rtx1210 firmware
≤ 14.01.38

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-829

Limiting P2P file sharing technology reduces inclusion of functionality or resources from untrusted external control spheres.

addresses: CWE-829

Enforcing installation policies prevents users from including functionality obtained from untrusted control spheres.

addresses: CWE-829

The inventory process requires identifying and recording the origin of all components, making inclusion of functionality from untrusted control spheres easier to detect during reviews.

addresses: CWE-829

Requiring approval and monitoring of maintenance tools prevents inclusion and execution of functionality obtained from untrusted sources.

addresses: CWE-829

Unowned portable devices represent untrusted control spheres; the prohibition prevents inclusion of functionality or data from such sources.

addresses: CWE-829

Strategy mandates assessment of third-party components and suppliers, directly reducing inclusion of functionality from untrusted control spheres.

addresses: CWE-829

Procedures can mandate supply-chain vetting and restrictions on functionality obtained from untrusted third-party or external control spheres.

addresses: CWE-829

Requires use of trusted sources and provenance tracking, tangibly limiting inclusion of functionality from untrusted control spheres.

References