CVE-2025-9091Public exploit

Root access via crackable embedded password hash

Published Aug 17, 2025 · Updated Aug 18, 2025

Hard-coded credentials in Tenda AC20 16.03.08.12 allow local users to recover the root password from the router firmware. The firmware ships a reusable MD5-crypt root password hash in /etc_ro/shadow, and the published proof cracks it to a fixed plaintext value. A local low-privileged user who can obtain and extract the firmware can recover credentials that grant root access to the router.

CVSS severity7.8
High
EPSS probability0.22%
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 Tenda AC20 16.03.08.12 allow local users to recover the root password from the router firmware. The firmware ships a reusable MD5-crypt root password hash in /etc_ro/shadow, and the published proof cracks it to a fixed plaintext value. A local low-privileged user who can obtain and extract the firmware can recover credentials that grant root access to the router.

The record

CVE
CVE-2025-9091
Published
Aug 17, 2025
Updated
Aug 18, 2025
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
AC20
Classifications
CWE-798, CWE-259, T1110.002, T1003.008
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 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=16.03.08.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · AC20version=16.03.08.12

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
1.1VulDB CNACVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E: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.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-798Hard-coded Credentials
CWE-259Use of Hard-coded Password
T1110.002Password Cracking
T1003.008OS Credential Dumping: /etc/passwd and /etc/shadow

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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