SecPod

Learn Search

Search across all Learn content

← Back to Security Research
CVE-2023-34990: Critical Path Traversal Flaw Found in Fortinet FortiWLM

CVE-2023-34990: Critical Path Traversal Flaw Found in Fortinet FortiWLM

On 12 May 2023, Horizon3 researcher Zach Hanley found an unauthenticated limited file read vulnerability in FortiWLM that he promptly disclosed to Fortinet. On 18 December 2024, it was given a name—CVE-2023-34990—and Fortinet released an advisory warning users of its severity.

Dec 19, 2024By Meghana Raatni2 min read

On 12 May 2023, Horizon3 researcher Zach Hanley found an unauthenticated limited file read vulnerability in FortiWLM that he promptly disclosed to Fortinet. On 18 December 2024, it was given a name—CVE-2023-34990—and Fortinet released an advisory warning users of its severity.

This flaw brought with it a critical CVSS rating of 9.8, allowing unauthenticated attackers to use improper input validation to read sensitive log files on affected systems. These files frequently contain administrator session IDs, which attackers can use to bypass authentication and gain privileged access to victims’ devices.

Technical Details

CVE-2023-34990’s limited file read can be found at the /ems/cgi-bin/ezrf_lighttpd.cgi endpoint, where a threat actor can traverse paths to read arbitrary system log files. The offending endpoint is located at /opt/meru/etc/ws/cgi-bin/ezrf_lighttpd.cgi and does not correctly validate request parameters when parsing them.

One such parameter is op_type. When a request sets op_type to upgradelogs, control is given to the upgradelogs() function, which returns the content of the log file specified within the variable $filename in the response. Using the imagename parameter, an attacker can perform a simple path traversal like so:

/ems/cgi-bin/ezrf_lighttpd.cgi?op_type=upgradelogs&imagename=../../../../../../../../data/apps/nms/logs/httpd_error_log

The response to this request should contain an administrator’s session ID in the set-cookie header, which can now be used to take over a vulnerable system.

Affected Products

Impact

Exploitation of this CVE can lead to network-wide disruptions for organizations that use FortiWLM, since unauthenticated attackers can use it to gain complete access to devices, and even chain it with CVE-2023-48782) to perform remote code execution in the context of root.

Solutions

Fortinet Wireless LAN Manager versions 8.6.6 and 8.5.5 contain patches. Fortinet recommends immediately upgrading to either of these (or any newer release).

Instantly Fix Risks with SanerNow Patch Management

SanerNow patch management is a continuous, automated, and integrated software that instantly fixes risks exploited in the wild. The software supports major operating systems like Windows, Linux, and macOS, as well as 550+ third-party applications.

It also allows you to set up a safe testing area to test patches before deploying them in a primary production environment. SanerNow patch management additionally supports a patch rollback feature in case of patch failure or a system malfunction.

Experience the fastest and most accurate patching software here.

Featured Posts

Open One Request, Total Persistence: Inside the SharePoint Flaw Attackers Are Exploiting
One Request, Total Persistence: Inside the SharePoint Flaw Attackers Are Exploiting

CVE Research

One Request, Total Persistence: Inside the SharePoint Flaw Attackers Are Exploiting

A critical SharePoint deserialization flaw, CVE-2026-50522 (CVSS 9.8), is under active exploitation just weeks after its July 2026 patch, following a public PoC. Attackers are using it to steal IIS machine keys in a single request, gaining persistence that survives patching alone. Now on CISA's KEV list, it's the third actively exploited SharePoint flaw in recent months, patch immediately and rotate machine keys.

Jul 24, 2026

Open ENCFORGE Ransomware: Anatomy of an AI-Focused Cyber Attack
ENCFORGE Ransomware: Anatomy of an AI-Focused Cyber Attack

CVE Research

ENCFORGE Ransomware: Anatomy of an AI-Focused Cyber Attack

Jul 22, 2026

Open UTA0533 Weaponizes KNUCKLEBALL: Inside the SonicWall SMA Zero-Day Exploitation Chain
UTA0533 Weaponizes KNUCKLEBALL: Inside the SonicWall SMA Zero-Day Exploitation Chain

CVE Research

UTA0533 Weaponizes KNUCKLEBALL: Inside the SonicWall SMA Zero-Day Exploitation Chain

Jul 20, 2026

Open One Email, Full Session Takeover: Inside Zimbra's Critical Classic Web Client Code Execution Flaw
One Email, Full Session Takeover: Inside Zimbra's Critical Classic Web Client Code Execution Flaw

CVE Research

One Email, Full Session Takeover: Inside Zimbra's Critical Classic Web Client Code Execution Flaw

Jul 20, 2026

CVE-2023-34990: Critical Path Traversal Flaw Found in Fortinet FortiWL | SecPod