Cyber Resilience

CVE-2024-39787

CriticalPublic PoC

Published: 14 January 2025

Published
14 January 2025
Modified
03 November 2025
KEV Added
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Patch
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CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0028 51.4th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-39787 is a critical-severity Path Traversal (CWE-22) vulnerability in Wavlink Wl-Wn533A8 Firmware. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 48.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and AC-3 (Access Enforcement).

Deeper analysis

CVE-2024-39787 involves multiple directory traversal vulnerabilities in the nas.cgi add_dir() functionality of the Wavlink AC3000 router running firmware version M33A8.V5030.210505. These issues, tied to CWE-22, enable a specially crafted HTTP request to bypass permissions. A specific directory traversal vulnerability also exists within the `disk_part` POST parameter. The vulnerability carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H) and was published on 2025-01-14.

Exploitation requires an authenticated attacker with high privileges (PR:H) to send a malicious HTTP request, triggering the directory traversal and permission bypass. Successful attacks can achieve high impacts on confidentiality, integrity, and availability with a changed scope (S:C), potentially granting unauthorized access to arbitrary files and directories on the device.

Mitigation guidance is available in the Talos Intelligence advisory at https://talosintelligence.com/vulnerability_reports/TALOS-2024-2057.

EU & UK References

Vulnerability details

Multiple directory traversal vulnerabilities exist in the nas.cgi add_dir() functionality of Wavlink AC3000 M33A8.V5030.210505. A specially crafted HTTP request can lead to permission bypass. An attacker can make an authenticated HTTP request to trigger these vulnerabilities.A directory traversal vulnerability exists…

more

within the `disk_part` POST parameter.

CWE(s)
CWE-22

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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 →
Why these techniques?

Directory traversal in public-facing router web CGI (nas.cgi) directly enables exploitation of the application for file/directory access and permission bypass.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2024-39786Same product: Wavlink Wl-Wn533A8
CVE-2024-39604Same product: Wavlink Wl-Wn533A8
CVE-2024-39803Same product: Wavlink Wl-Wn533A8
CVE-2024-37184Same product: Wavlink Wl-Wn533A8
CVE-2024-34166Same product: Wavlink Wl-Wn533A8
CVE-2024-39790Same product: Wavlink Wl-Wn533A8
CVE-2024-39768Same product: Wavlink Wl-Wn533A8
CVE-2024-36290Same product: Wavlink Wl-Wn533A8
CVE-2024-39603Same product: Wavlink Wl-Wn533A8
CVE-2024-39794Same product: Wavlink Wl-Wn533A8

Affected Assets

wavlink
wl-wn533a8 firmware
m33a8.v5030.210505

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly mitigates directory traversal in nas.cgi add_dir() and disk_part POST parameter by validating inputs to block malicious paths like '../'.

AC-3 Access Enforcement partial match
prevent

Enforces access control policies to prevent permission bypass and unauthorized file/directory access despite crafted HTTP requests.

AC-6 Least Privilege partial match
prevent

Limits privileges of authenticated users to least necessary, reducing impact of high-privilege (PR:H) exploitation for arbitrary file access.

References