CVE-2021-34236Network attack vector

Remote code execution via register_country overflow

Published Sep 7, 2022 · Updated Aug 4, 2024

Buffer overflow in NETGEAR R8000 firmware 1.0.4.56 allows remote attackers to execute arbitrary code or cause denial of service via a crafted POST request. The /bd_genie_create_account.cgi handler copies an overlong register_country parameter without sufficient bounds checking, corrupting memory. The endpoint is reachable over the network without authentication in the published record, so a crafted request can crash the router or provide code execution depending on memory-control outcomes.

CVSS severity9.8
Critical
EPSS probability1.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in NETGEAR R8000 firmware 1.0.4.56 allows remote attackers to execute arbitrary code or cause denial of service via a crafted POST request. The /bd_genie_create_account.cgi handler copies an overlong register_country parameter without sufficient bounds checking, corrupting memory. The endpoint is reachable over the network without authentication in the published record, so a crafted request can crash the router or provide code execution depending on memory-control outcomes.

The record

CVE
CVE-2021-34236
Published
Sep 7, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 7, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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