CVE-2020-9276Network attack vector

Code execution via unchecked CGI URL copy

Published Apr 20, 2020 · Updated Aug 4, 2024

Stack-based buffer overflow in do_cgi in D-Link DSL-2640B B2 EU_4.01B allows remote authenticated users to execute arbitrary code. The function copies an incoming URL into a local stack variable without checking its length, allowing the URL to overwrite the return address. Direct exploitation requires authentication and LAN or Wi-Fi access; chaining CVE-2020-9277 bypasses authentication and grants full device control.

CVSS severity8.8
High
EPSS probability2.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in do_cgi in D-Link DSL-2640B B2 EU_4.01B allows remote authenticated users to execute arbitrary code. The function copies an incoming URL into a local stack variable without checking its length, allowing the URL to overwrite the return address. Direct exploitation requires authentication and LAN or Wi-Fi access; chaining CVE-2020-9277 bypasses authentication and grants full device control.

The record

CVE
CVE-2020-9276
Published
Apr 20, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1190
Attack vector
network
Privileges
authenticated

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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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