CVE-2021-35324Public exploitNetwork attack vector

Unauthenticated administrator access via trusted authCode

Published Aug 5, 2021 · Updated Aug 4, 2024

Authentication bypass in TOTOLINK A720R firmware 4.1.5cu.470_B20200911 allows remote attackers to access the administrator page. Form_Login accepts the authCode URL parameter and skips its credential check when getNthValueSafe returns the attacker-supplied value 1. An unauthenticated GET request with authCode=1 and userName=admin is sufficient to enter the administrative interface without a password.

CVSS severity9.8
Critical
EPSS probability10.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in TOTOLINK A720R firmware 4.1.5cu.470_B20200911 allows remote attackers to access the administrator page. Form_Login accepts the authCode URL parameter and skips its credential check when getNthValueSafe returns the attacker-supplied value 1. An unauthenticated GET request with authCode=1 and userName=admin is sufficient to enter the administrative interface without a password.

The record

CVE
CVE-2021-35324
Published
Aug 5, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2021CVE 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

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS: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 exploitPublished

Weakness, pattern, technique

T1190Exploit Public-Facing Application

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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