CVE-2021-34862

Root code execution via menu parameter overflow

Published Oct 25, 2021 · Updated Aug 4, 2024

Stack-based buffer overflow in D-Link DAP-2020 1.01 and earlier allows remote attackers to execute arbitrary code as root. The webproc endpoint copies the untrusted var:menu parameter into a fixed-length stack buffer without validating its length, allowing an overflow. No authentication or user interaction is required, but the attacker must reach the appliance from an adjacent network.

CVSS severity8.8
High
EPSS probability0.82%
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 D-Link DAP-2020 1.01 and earlier allows remote attackers to execute arbitrary code as root. The webproc endpoint copies the untrusted var:menu parameter into a fixed-length stack buffer without validating its length, allowing an overflow. No authentication or user interaction is required, but the attacker must reach the appliance from an adjacent network.

The record

CVE
CVE-2021-34862
Published
Oct 25, 2021
Updated
Aug 4, 2024
Vendor
D-Link
Product
DAP-2020
Classifications
CWE-121, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 25, 2021CVE 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?

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

  1. Affected versionversion=1.01rc001

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

D-Link · DAP-2020version=1.01rc001

Published CVSS scores

8.8NISTCVSS:3.1/AV:A/AC:L/PR:N/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
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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