CVERadar
HIGH · CVSS 3.1 8.8CISA KEV · added 2023-05-01Exploit-DBPublic PoCEPSS 100.00% (p100)Threat level 89

CVE-2023-1389: TP-Link Archer AX-21 Command Injection Vulnerability

TP-Link · Archer AX21 · NVD published 2023-03-16 · posted 2026-10-21 · last modified 2026-06-17

What it is

TP-Link Archer AX21 (AX1800) firmware versions before 1.1.4 Build 20230219 contained a command injection vulnerability in the country form of the /cgi-bin/luci;stok=/locale endpoint on the web management interface. Specifically, the country parameter of the write operation was not sanitized before being used in a call to popen(), allowing an unauthenticated attacker to inject commands, which would be run as root, with a simple POST request.

WeaknessCWE-77
CVSS vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (source: [email protected])
CISA due date2023-05-22 (for US federal agencies under BOD; a good deadline for everyone)
ATT&CK tacticsExecution → Stealth → Exfiltration → Impact

Exploitation evidence

First exploit evidence seen: 2023-05-01 (earliest date across the sources below).

Exploited in the wild

  • CISA KEV: listed since 2023-05-01. Source

Public exploit code

Exploit-DB

  • EDB-51677: TP-Link Archer AX21 - Unauthenticated Command Injection (2023-08-10)

GitHub proof-of-concept repositories

2 public repositories from 2 accounts, first seen 2023-07-28. Most starred: Voyag3r-Security/CVE-2023-1389 (17 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · Exploit-DB (OffSec) · nomi-sec/PoC-in-GitHub.

Defend the Chain

The attack chain for CVE-2023-1389 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.

Threat level 89/100
Defender level 1 · 0 XP
Chain links broken: 0/5

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Stealth

Defense Impairment

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Pick a red technique card on the board, then choose the defence that stops it.

Defend against T1106 Native API CTID: exploitation technique

CVE-2023-1389 is a command injection vulnerability in one of the API components within the TP-Link Archer router’s web management interface. Public reports have reported that multiple botnet malware under the Mirai variants, including Condi, are targeting these vulnerable devices.

How to fix it

CISA required action

Apply updates per vendor instructions. (source: CISA KEV)

Fixed versions

  • tp-link archer ax21 firmware: upgrade to 1.1.4 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

MITRE ATT&CK mitigations for this chain

  • M1038 Execution Prevention (for T1106) : Identify and block potentially malicious software executed that may be executed through this technique by using application control tools, like Windows Defender Application Control, AppLocker, or Software Restriction Policies where appropriate.
  • M1040 Behavior Prevention on Endpoint (for T1106) : On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent Office VBA macros from calling Win32 APIs.
  • M1041 Encrypt Sensitive Information (for T1070) : Obfuscate/encrypt event files locally and in transit to avoid giving feedback to an adversary.
  • M1029 Remote Data Storage (for T1070) : Automatically forward events to a log server or data repository to prevent conditions in which the adversary can locate and manipulate data on the local system. When possible, minimize time delay on event reporting to avoid prolonged storage on the local system.
  • M1022 Restrict File and Directory Permissions (for T1070) : Protect generated event files that are stored locally with proper permissions and authentication and limit opportunities for adversaries to increase privileges by preventing Privilege Escalation opportunities.
  • M1031 Network Intrusion Prevention (for T1041) : Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level. Signatures are often for unique indicators within protocols and may be based on the specific obfuscation technique used by a particular
  • M1057 Data Loss Prevention (for T1041) : Data loss prevention can detect and block sensitive data being sent over unencrypted protocols.
  • M1037 Filter Network Traffic (for T1498) : When flood volumes exceed the capacity of the network connection being targeted, it is typically necessary to intercept the incoming traffic upstream to filter out the attack traffic from the legitimate traffic. Such defenses can be provided by the hosting Internet Service Provider (ISP) or by a 3rd party such as a Con

Detection Generic guidance

  • Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
  • Exfiltration: Watch for large or unusual outbound transfers from the affected host.
  • Impact: Monitor service availability, unexpected encryption activity and mass file changes.

Response checklist Generic guidance

  1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
  2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
  3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
  4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Sources