CVE-2025-6139Public exploit

Root shell access via hard-coded shadow password

Published Jun 16, 2025 · Updated Jun 17, 2025

Hard-coded credentials in TOTOLINK T10 4.1.8cu.5207 allow remote authenticated users on the local network to obtain root shell access. The rcS startup scripts copy a fixed root password hash from /etc/shadow.sample into the live shadow file, making the same recoverable password valid on each device. Exploitation requires privileged local-network access and a reachable Telnet service; successful authentication grants a root shell on the router.

CVSS severity2.0
Low
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hard-coded credentials in TOTOLINK T10 4.1.8cu.5207 allow remote authenticated users on the local network to obtain root shell access. The rcS startup scripts copy a fixed root password hash from /etc/shadow.sample into the live shadow file, making the same recoverable password valid on each device. Exploitation requires privileged local-network access and a reachable Telnet service; successful authentication grants a root shell on the router.

The record

CVE
CVE-2025-6139
Published
Jun 16, 2025
Updated
Jun 17, 2025
Vendor
TOTOLINK
Product
T10
Classifications
CWE-255, CWE-259, T1078
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 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.5207

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

TOTOLINK · T10version=4.1.8cu.5207

Published CVSS scores

2.0VulDBCVSS:4.0/AV:A/AC:H/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
3.9VulDBCVSS:3.0/AV:A/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
3.7VulDBAV:A/AC:H/Au:M/C:P/I:P/A:P
3.9VulDBCVSS:3.1/AV:A/AC:H/PR:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-255Credentials Management Errors
CWE-259Use of Hard-coded Password
T1078Valid Accounts

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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