CVE-2025-9533Network attack vector

Unauthenticated login via authCode value manipulation

Published Aug 27, 2025 · Updated Aug 27, 2025

Improper authentication in TOTOLINK T10 4.1.8cu.5241_B20210927 allows remote attackers to bypass login via a crafted authCode. The /formLoginAuth.htm handler processes authCode=1 in a way that defeats its normal authentication check; the underlying function is undisclosed. Network access to the router web management interface is required, and exploitation grants access otherwise gated by login.

CVSS severity7.3
High
EPSS probability9.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in TOTOLINK T10 4.1.8cu.5241_B20210927 allows remote attackers to bypass login via a crafted authCode. The /formLoginAuth.htm handler processes authCode=1 in a way that defeats its normal authentication check; the underlying function is undisclosed. Network access to the router web management interface is required, and exploitation grants access otherwise gated by login.

The record

CVE
CVE-2025-9533
Published
Aug 27, 2025
Updated
Aug 27, 2025
Vendor
TOTOLINK
Product
T10
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2025Record 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=4.1.8cu.5241_B20210927

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TOTOLINK · T10version=4.1.8cu.5241_B20210927

Published CVSS scores

7.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
6.9VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
5.5VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-287Improper Authentication
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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