Cyber Resilience

CVE-2023-39747

CriticalPublic PoC

Published: 21 August 2023

Published
21 August 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1254 94.1th percentile
Risk Priority 27 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-39747 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Tp-Link Tl-Wr940N V2 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 5.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

TP-Link WR841N V8, TL-WR940N V2, and TL-WR941ND V5 routers contain a stack-based buffer overflow vulnerability (CWE-120) triggered by the radiusSecret parameter in the /userRpm/WlanSecurityRpm endpoint. The flaw received a CVSS 3.1 score of 9.8, reflecting network-accessible input handling without authentication or user interaction.

An unauthenticated remote attacker can supply a crafted radiusSecret value to overflow the buffer, resulting in arbitrary code execution with full control over the device confidentiality, integrity, and availability. The attack requires only a single HTTP request to the management interface and succeeds against the listed firmware versions.

Public references consist of technical write-ups hosted on GitHub that document the parameter handling and reproduction steps; no vendor advisory, firmware patch, or mitigation guidance is referenced in the available sources. The associated EPSS score has remained flat at 0.1254 with no material increase since disclosure.

EU & UK References

Vulnerability details

TP-Link WR841N V8, TP-Link TL-WR940N V2, and TL-WR941ND V5 were discovered to contain a buffer overflow via the radiusSecret parameter at /userRpm/WlanSecurityRpm.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

tp-link
tl-wr940n v2 firmware
all versions
tp-link
tl-wr941nd v5 firmware
all versions
tp-link
tl-wr841n v8 firmware
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

References