CVE-2018-13374
CVE-2018-13374 is a security flaw in Fortinet FortiOS and FortiADC, the operating system on Fortinet’s FortiGate firewalls. Attackers can reach parts of Fortinet FortiOS and FortiADC that should be locked to them. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 8 Sep 2022, and says ransomware gangs have used it.[1]
Fortinet FortiOS and FortiADC is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fortinet has published a fix or advice.
Description
CISA calls it an improper access control in Fortinet FortiOS and FortiADC. In its words: “Fortinet FortiOS and FortiADC contain an improper access control vulnerability that allows attackers to obtain the LDAP server login credentials configured in FortiGate by pointing a LDAP server connectivity test request to a rogue LDAP server.”[1]
The CVE record adds: “A Improper Access Control in Fortinet FortiOS 6.0.2, 5.6.7 and before, FortiADC 6.1.0, 6.0.0 to 6.0.1, 5.4.0 to 5.4.4 allows attacker to obtain the LDAP server login credentials configured in FortiGate via pointing a LDAP server connectivity test request to a rogue LDAP server instead of the configured one.”[2]
The underlying weakness is incorrect permissions (CWE-732), in MITRE’s list of common software weaknesses.
It scores 4.3 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Fortinet’s advisory has them[3]. CISA names the product as Fortinet FortiOS and FortiADC.
Most families won’t have Fortinet FortiOS and FortiADC; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 8 Sep 2022, 1,325 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 29 Sep 2022 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 38%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Fortinet has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Fortinet FortiOS and FortiADC is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 29 Sep 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 4.3.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 38%.[4] |
See also
Other Fortinet flaws
- CVE-2025-61624, Fortinet products: path traversal ·
- CVE-2026-104286, Fortinet FortiMail: path traversal ·
- CVE-2025-25249, Fortinet products: heap-based buffer overflow ·
- CVE-2025-68686, Fortinet FortiOS: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-39808, Fortinet FortiSandbox: OS command injection ·
Other incorrect permissions flaws
- CVE-2019-15752, Docker Desktop Community Edition: privilege escalation ·
Added the same day
- CVE-2022-3075, Chrome and other Chromium browsers: insufficient data validation ·
- CVE-2022-27593, QNAP Photo Station: externally controlled reference ·
- CVE-2022-26258, D-Link DIR-820L: remote code execution ·
- CVE-2020-9934, Apple iOS, iPadOS, and macOS: input validation ·
- CVE-2018-7445, MikroTik RouterOS: stack-based buffer overflow ·
Every Fortinet flaw on CISA’s list · Everything added in September 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Fortinet FortiOS and FortiADC Improper Access Control Vulnerability”. Known Exploited Vulnerabilities Catalog, added 8 Sep 2022.
- ^ National Institute of Standards and Technology. “CVE-2018-13374 Detail”. National Vulnerability Database, published 22 Jan 2019.
- ^ Fortinet. Advisories and fixes: fortiguard.com, fortiguard.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.381, percentile 98.6, 31 Oct 2026.
- CVE Program. “CVE-2018-13374”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.