CVE-2025-8231Public exploit

Physical root access via hard-coded UART credential

Published Jul 27, 2025 · Updated Jul 28, 2025

Hard-coded UART credentials in D-Link DIR-890L firmware 111b04 and earlier allow physically proximate attackers to gain root access. The rgbin binary's authentication function at address 0xD084 compares UART input with a credential read from system configuration and falls back to a compiled credential when UART is enabled. Physical access to the router and an enabled UART interface are required; successful authentication provides unrestricted root control of the appliance.

CVSS severity6.8
Medium
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Hard-coded UART credentials in D-Link DIR-890L firmware 111b04 and earlier allow physically proximate attackers to gain root access. The rgbin binary's authentication function at address 0xD084 compares UART input with a credential read from system configuration and falls back to a compiled credential when UART is enabled. Physical access to the router and an enabled UART interface are required; successful authentication provides unrestricted root control of the appliance.

The record

CVE
CVE-2025-8231
Published
Jul 27, 2025
Updated
Jul 28, 2025
Vendor
D-Link
Product
DIR-890L
Classifications
CWE-259, CWE-798, T1078
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=111b04

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

D-Link · DIR-890Lversion=111b04

Published CVSS scores

6.8VulDB CNACVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.2VulDB CNACVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
7.2VulDB CNAAV:L/AC:L/Au:N/C:C/I:C/A:C

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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-259Use of Hard-coded Password
CWE-798Use of Hard-coded Credentials
T1078Valid Accounts

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo