Cyber Resilience

CVE-2023-33538

RCE in Tp-Link Tl-Wr940N Firmware

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCECommand Injection
Published
07 June 2023
Modified
27 October 2025
KEV Added
16 June 2025
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.42 99th percentile
Risk Priority 90 floored blend · peak EPSS

Summary

CVE-2023-33538 is a high-severity Command Injection (CWE-77) vulnerability in Tp-Link Tl-Wr940N. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-33538 is a command injection vulnerability, tracked under CWE-77, that affects the TP-Link TL-WR940N V2/V4, TL-WR841N V8/V10, and TL-WR740N V1/V2 wireless routers. The flaw resides in the /userRpm/WlanNetworkRpm component and carries a CVSS 3.1 base score of 8.8.

An authenticated attacker with network access can supply crafted input to the affected endpoint and execute arbitrary commands on the device. Successful exploitation grants the attacker full control over the router, enabling actions such as altering configuration, intercepting traffic, or pivoting into the local network.

Public references indicate that CISA has issued a warning specifically addressing active exploitation of this vulnerability. No vendor-supplied patches or configuration workarounds are detailed in the available references.

The EPSS score currently stands at 0.9091 with a recorded peak of 0.9147, and one advisory source explicitly notes ongoing in-the-wild exploitation activity.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

TP-Link TL-WR940N V2/V4, TL-WR841N V8/V10, and TL-WR740N V1/V2 was discovered to contain a command injection vulnerability via the component /userRpm/WlanNetworkRpm .

CWE(s)
CWE-77
KEV Date Added
16 June 2025

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
T1059.008 Network Device CLI Execution
Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-1389Same vendor: Tp-Linkboth on KEV
CVE-2023-33536Same product: Tp-Link Tl-Wr740N
CVE-2023-33537Same product: Tp-Link Tl-Wr740N
CVE-2023-27078Same vendor: Tp-Link
CVE-2023-43138Same vendor: Tp-Link
CVE-2023-39471Same product: Tp-Link Tl-Wr841N
CVE-2023-31701Same vendor: Tp-Link
CVE-2025-14756Same vendor: Tp-Link
CVE-2025-15607Same vendor: Tp-Link
CVE-2021-4045Same vendor: Tp-Link

Affected Assets

tp-link
tl-wr940n firmware
all versions
tp-link
tl-wr841n firmware
all versions
tp-link
tl-wr740n firmware
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.3
  • V1.2.5
  • V1.2.8
  • V1.2.9

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and neutralization that prevent command injection.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches command-injection vulnerabilities before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and command construction practices that directly prevent command injection.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for controls against injection flaws including command injection.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the attack surface but do not prescribe the specific neutralization techniques needed.

A.8.31 Separation of development, test and production environments none match
none

Environment separation limits the blast radius of an exploited command injection but does not prevent the flaw itself.

References