CVE-2015-5736

Fortinet FortiClient < 5.2.3 - Local Privilege Escalation via Fortishield.sys Ioctl Calls

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 4 public exploits for CVE-2015-5736. PoCs published by sickness & mschenk, sickness, avielzecharia.

AI-analyzed exploit summary This exploit targets CVE-2015-5736, a privilege escalation vulnerability in FortiShield.sys. It leverages memory leaks and ROP chains to achieve arbitrary code execution in kernel mode, ultimately spawning a command prompt with elevated privileges.

Description

The Fortishield.sys driver in Fortinet FortiClient before 5.2.4 allows local users to execute arbitrary code with kernel privileges by setting the callback function in a (1) 0x220024 or (2) 0x220028 ioctl call.

Exploits (4)

exploitdb WORKING POC VERIFIED
by sickness & mschenk · c++localwindows_x86-64
https://www.exploit-db.com/exploits/45149

This exploit targets CVE-2015-5736, a privilege escalation vulnerability in FortiShield.sys. It leverages memory leaks and ROP chains to achieve arbitrary code execution in kernel mode, ultimately spawning a command prompt with elevated privileges.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: FortiShield.sys (Fortinet FortiClient)
No auth needed
Prerequisites: Access to the vulnerable system · Presence of FortiShield.sys driver · Ability to interact with the driver via DeviceIoControl
devstral-2 · analyzed Feb 16, 2026 Full analysis →
exploitdb WORKING POC VERIFIED
by sickness · clocalwindows_x86-64
https://www.exploit-db.com/exploits/41721

This exploit leverages a vulnerability in FortiShield.sys to bypass SMEP (Supervisor Mode Execution Prevention) by manipulating PTE (Page Table Entries) and executing a token-stealing payload for local privilege escalation on Windows 10 Pro x64 (Pre-Anniversary).

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: FortiShield.sys 5.2.3.633 on Windows 10 Pro x64 (Pre-Anniversary)
No auth needed
Prerequisites: Presence of vulnerable FortiShield.sys driver · Local access to the target system
devstral-2 · analyzed Feb 16, 2026 Full analysis →
exploitdb WORKING POC VERIFIED
by sickness · clocalwindows_x86-64
https://www.exploit-db.com/exploits/41722

This exploit leverages a use-after-free vulnerability in the Windows kernel (CVE-2015-5736) to achieve local privilege escalation by manipulating bitmap objects and accelerator tables to corrupt kernel memory. It includes a ROP chain to bypass SMEP and execute arbitrary code in kernel mode.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: Windows 10 Pro x64 (Post-Anniversary) with FortiShield.sys 5.2.3.633
No auth needed
Prerequisites: Windows 10 Pro x64 (Post-Anniversary) · FortiShield.sys 5.2.3.633 · Local access to the system
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 3 stars
by avielzecharia · poc
https://github.com/avielzecharia/CVE-2015-5736

This PoC exploits CVE-2015-5736 in FortiShield.sys using ROP chains, PreviousMode overwrite, and token stealing to achieve local privilege escalation. It leverages a race condition in MoveFileEx and arbitrary read/write primitives to manipulate kernel memory.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Racy
Target: FortiShield.sys (Fortinet FortiShield)
No auth needed
Prerequisites: Windows system with FortiShield.sys driver loaded · Local access to the target system
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (10)

Core 10
Core References
Exploit, Third Party Advisory exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/41722/
Exploit, Third Party Advisory exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/45149/
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1033439
Exploit, Third Party Advisory exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/41721/
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/536369/100/0/threaded
Mailing List mailing-list x_refsource_fulldisc
http://seclists.org/fulldisclosure/2015/Sep/0

Scores

EPSS 0.0255
EPSS Percentile 85.8%

Details

CWE
CWE-264
Status published
Products (1)
fortinet/forticlient < 5.2.3
Published Sep 03, 2015
Tracked Since Feb 18, 2026