Privilege escalation via OpenSSL engine DLL hijacking
Published Nov 14, 2023 · Updated Dec 16, 2025
Untrusted DLL search in Fortinet FortiClient for Windows 7.0.9 and 7.2.0 through 7.2.1 allows local users to escalate privileges. Its OpenSSL component processes openssl.cnf and loads a referenced engine library from an attacker-controlled search-path location without constraining the DLL source. Local low-privileged access is required; successful hijacking executes attacker-supplied code in the FortiClient process context.
Summary
What happened
Untrusted DLL search in Fortinet FortiClient for Windows 7.0.9 and 7.2.0 through 7.2.1 allows local users to escalate privileges. Its OpenSSL component processes openssl.cnf and loads a referenced engine library from an attacker-controlled search-path location without constraining the DLL source. Local low-privileged access is required; successful hijacking executes attacker-supplied code in the FortiClient process context.
The record
- CVE
- CVE-2023-41840
- Published
- Nov 14, 2023
- Updated
- Dec 16, 2025
- Vendor
- Fortinet
- Product
- FortiClient for Windows
- Classifications
- CWE-426, T1574.002
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 14, 2023CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.0.9
- Affected versionversion=7.2.0 <=7.2.1
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo