CVE-2021-35003Network attack vector

Unauthenticated root code execution via DNS response overflow

Published Jan 21, 2022 · Updated Aug 4, 2024

Stack-based buffer overflow in TP-Link Archer C90 firmware 1.0.6 Build 20200114 rel.73164(5553) allows remote attackers to execute code. A crafted DNS response overflows a fixed-length stack buffer in the router's DNS response handler. No authentication or user interaction is required, and successful exploitation runs attacker-supplied code as root.

CVSS severity9.8
Critical
EPSS probability7.74%
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 TP-Link Archer C90 firmware 1.0.6 Build 20200114 rel.73164(5553) allows remote attackers to execute code. A crafted DNS response overflows a fixed-length stack buffer in the router's DNS response handler. No authentication or user interaction is required, and successful exploitation runs attacker-supplied code as root.

The record

CVE
CVE-2021-35003
Published
Jan 21, 2022
Updated
Aug 4, 2024
Vendor
TP-Link
Product
Archer C90
Classifications
CWE-121
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 21, 2022CVE 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=1.0.6 Build 20200114 rel.73164(5553)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TP-Link · Archer C90version=1.0.6 Build 20200114 rel.73164(5553)

Published CVSS scores

10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8Zero Day InitiativeCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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