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Archer Ax21 FirmwareOperating system · Tp Link

CVE-2023-27333

MEDIUM · 6.8 CVSS v3.0 Published 2024-05-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
TP-Link Archer AX21 tmpServer Command 0x422 Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of TP-Link Archer AX21 routers. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of command 0x422 provided to the tmpServer service. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. . Was ZDI-CAN-19905.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack-based buffer overflow vulnerability exists in the tmpServer service of TP-Link Archer AX21 routers when handling command 0x422. The service fails to validate the length of user-supplied data before copying it to a fixed-size stack buffer, allowing an attacker to overflow the buffer and achieve remote code execution with root privileges.

MitigationApply the vendor-supplied firmware update from TP-Link for the Archer AX21. Until the patch is available, disable the tmpServer service if possible and isolate the device behind a network boundary to reduce exposure to adjacent network attackers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Archer Ax21 FirmwareOperating system
Affected:= 1.1.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device model
    Log into the router's web interface or check the device label to confirm the model is TP-Link Archer AX21
    Affected if The device is not a TP-Link Archer AX21
  2. Check the firmware version
    Navigate to the router's web interface (typically at 192.168.0.1), go to Administration > Firmware Upgrade, or use the TP-Link Tether app to view the current firmware version
    Affected if The firmware version is 1.1.3
  3. Verify the tmpServer service is running
    Access the router via SSH (if enabled) and run 'ps | grep tmpServer' or check the router's running processes via the web interface under System Tools > Diagnostics
    Affected if The tmpServer process is actively running on the device
  4. Check network exposure of the tmpServer service
    Review router firewall settings and port forwards to determine if the tmpServer service (typically listens on port 9010 or similar admin ports) is accessible from the WAN or adjacent networks
    Affected if The tmpServer service port is exposed to untrusted networks or the WAN interface
  5. Confirm tmpServer is listening on the network
    From a computer on the LAN, use 'nmap -p 9010 <router_ip>' or 'netstat -an | grep 9010' to verify if the tmpServer port is open and listening
    Affected if Port 9010 (or the tmpServer admin port) is open and listening on the router's IP address

You are affected if you have a TP-Link Archer AX21 router running firmware version 1.1.3 with the tmpServer service running and exposed to the network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied firmware update from TP-Link for the Archer AX21. Until the patch is available, disable the tmpServer service if possible and isolate the device behind a network boundary to reduce exposure to adjacent network attackers.

Fix this in Archer Ax21 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-27333 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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