CVE-2021-20119Public exploit

Administrator account takeover via client-side verification bypass

Published Nov 9, 2021 · Updated Aug 3, 2024

Improper validation in ARRIS SURFboard SB8200 firmware allows remote authenticated users to change the administrator password. The changepwd_tab.html handler accepts a manually submitted password-change request because the current-password check runs only in the browser. Any valid user session can bypass that client-side check and take control of the administrator account, affecting confidentiality, integrity, and availability.

CVSS severity5.5
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper validation in ARRIS SURFboard SB8200 firmware allows remote authenticated users to change the administrator password. The changepwd_tab.html handler accepts a manually submitted password-change request because the current-password check runs only in the browser. Any valid user session can bypass that client-side check and take control of the administrator account, affecting confidentiality, integrity, and availability.

The record

CVE
CVE-2021-20119
Published
Nov 9, 2021
Updated
Aug 3, 2024
Vendor
ARRIS
Product
SURFboard SB8200
Classifications
T1098
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Arris SurfBoard SB8200 AB01.02.053.01_112320_193.0A.NSH

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

ARRIS · SURFboard SB8200version=Arris SurfBoard SB8200 AB01.02.053.01_112320_193.0A.NSH

Published CVSS scores

5.5TenableCVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1098Account Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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