What’s Vulnerable › Vulnerabilities
CVE-2021-20843
- Severity: medium (CVSS 5.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.7% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-11-24 · updated 2026-06-17
- Weakness: CWE-829
Description
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 specially crafted web page.
Affected products
- Ntt-West Biz Box Nvr510 Firmware: before 15.01.18 — fixed in 15.01.18
- Ntt-West Biz Box Nvr700W Firmware: through 15.00.19
- Ntt-West Biz Box Rtx1210 Firmware: through 14.01.38
- Ntt-West Biz Box Rtx830 Firmware: through 15.02.17
- Yamaha Nvr510 Firmware: through 15.01.18
- Yamaha Nvr700W Firmware: through 15.00.19
- Yamaha Rtx1210 Firmware: through 14.01.38
- Yamaha Rtx830 Firmware: through 15.02.17
How to fix
Upgrade to a fixed version: Ntt-West Biz Box Nvr510 Firmware 15.01.18. Check the vendor advisory for mitigations.
References
- http://www.rtpro.yamaha.co.jp/RT/FAQ/Security/JVNVU91161784.html
- https://business.ntt-east.co.jp/topics/2021/11_09.html
- https://jvn.jp/en/vu/JVNVU91161784/index.html
- https://www.ntt-west.co.jp/smb/kiki_info/info/211109.html
- http://www.rtpro.yamaha.co.jp/RT/FAQ/Security/JVNVU91161784.html
- https://business.ntt-east.co.jp/topics/2021/11_09.html
- https://jvn.jp/en/vu/JVNVU91161784/index.html
- https://www.ntt-west.co.jp/smb/kiki_info/info/211109.html
Get alerted when CVE-2021-20843 or the next vulnerability affects your stack