HOMEVULNERABILITIESCVE-2021-20844
MEDIUM

CVE-2021-20844

CWE-116Published: November 24, 2021· Updated: Jun 17, 2026

5.7
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-20844 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.7.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

Affected Vendors & Products

ntt-west8 product(s)
biz box rtx830 firmwarebiz box rtx830biz box nvr510 firmwarebiz box nvr510biz box nvr700w firmwarebiz box nvr700wbiz box rtx1210 firmwarebiz box rtx1210
yamaha8 product(s)
rtx830 firmwarertx830nvr510 firmwarenvr510nvr700w firmwarenvr700wrtx1210 firmwarertx1210
Source: NVD CPE · 16 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (8)

Quick Facts

CVE IDCVE-2021-20844
CVSS Score5.7 / 10
SeverityMEDIUM
WeaknessCWE-116
CISA KEVNo
Affected2 vendor(s)
PublishedNov 24, 2021

Related CVEs (CWE-116)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-20844 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.