CVE-2020-9279Public exploitNetwork attack vector

Device takeover via hard-coded privileged account

Published Apr 20, 2020 · Updated Aug 4, 2024

Hard-coded credentials in D-Link DSL-2640B B2 EU_4.01B firmware allow remote attackers to gain privileged device access. The cfm authentication path delegates credential checks to libpsi.so, which embeds an unremovable user account and password accepted by the web, FTP, Telnet, and SSH services. Reachability requires access to the LAN or Wi-Fi management interfaces, although a malicious website can pivot through a browser on that network; successful login permits security-setting changes and malicious firmware upload.

CVSS severity9.8
Critical
EPSS probability2.19%
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 D-Link DSL-2640B B2 EU_4.01B firmware allow remote attackers to gain privileged device access. The cfm authentication path delegates credential checks to libpsi.so, which embeds an unremovable user account and password accepted by the web, FTP, Telnet, and SSH services. Reachability requires access to the LAN or Wi-Fi management interfaces, although a malicious website can pivot through a browser on that network; successful login permits security-setting changes and malicious firmware upload.

The record

CVE
CVE-2020-9279
Published
Apr 20, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1078.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 20, 2020CVE 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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1078.001Valid Accounts: Default 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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