Actively exploited vulnerability
Fortinet FortiOS and FortiADC: improper access control flaw under attack
CVE-2018-13374 · Fortinet FortiOS and FortiADC Improper Access Control Vulnerability
What is affected
Fortinet FortiOS and FortiADC is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.
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.
What an attacker can do
This is a improper access control flaw. It lets an attacker perform actions or reach data that should be restricted to authorised users.
- How it is reached
- Over the internet or network
- Access the attacker needs
- A basic user account
- Does the victim have to do something?
- No, works without the victim doing anything
CISA records this vulnerability as known to be used in ransomware campaigns: attackers use it to get in, then encrypt files and demand payment.
What to do
- At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
- If you administer Fortinet FortiOS and FortiADC at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
- If the product is past its support date and no fix exists, take it off the internet or retire it.
Apply updates per vendor instructions.
Vendor advisories and fixes
- fortiguard.comwww.fortiguard.com/psirt/FG-IR-18-157
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on September 8, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by September 29, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 38% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99% of all scored vulnerabilities.
Its CVSS severity score is 4.3 out of 10 (medium), as recorded in the US National Vulnerability Database.
Technical description
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.