Improper neutralization of HTTP request headers for scripting syntax 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 obtain sensitive information via a specially crafted web page.
CVE-2021-20844
This medium-severity CVE scores 5.7 under NVD CVSS v3. EPSS exploit probability: 0.9%, top 43% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.7
- EG Score
- 5.7(medium)
- EG Risk
- —
- EPSS
- 56.7%
- KEV
- Not listed
Published
November 24, 2021
Last Modified
November 21, 2024
References (8)
- vultures@jpcerthttp://www.rtpro.yamaha.co.jp/RT/FAQ/Security/JVNVU91161784.html
- vultures@jpcerthttps://business.ntt-east.co.jp/topics/2021/11_09.html
- vultures@jpcerthttps://jvn.jp/en/vu/JVNVU91161784/index.html
- vultures@jpcerthttps://www.ntt-west.co.jp/smb/kiki_info/info/211109.html
- af854a3a-2127-422b-91ae-364da2661108http://www.rtpro.yamaha.co.jp/RT/FAQ/Security/JVNVU91161784.html
- af854a3a-2127-422b-91ae-364da2661108https://business.ntt-east.co.jp/topics/2021/11_09.html
- af854a3a-2127-422b-91ae-364da2661108https://jvn.jp/en/vu/JVNVU91161784/index.html
- af854a3a-2127-422b-91ae-364da2661108https://www.ntt-west.co.jp/smb/kiki_info/info/211109.html
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 46× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 22:43 UTCEG score recompute
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Related CVEs(same CWE)
Same CWE
10 shownCWE-116
Frequently asked(5)
What is CVE-2021-20844?
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Is CVE-2021-20844 actively exploited?
What is the CVSS score of CVE-2021-20844?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-20844
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