Security Experts:

Connect with us

Hi, what are you looking for?


Application Security

CISA, FBI Warn of Attacks Targeting Fortinet FortiOS

The U.S. government is warning that Advanced Persistent Threat (APT) actors are exploiting vulnerabilities in Fortinet FortiOS in ongoing attacks targeting commercial, government, and technology services networks.

The U.S. government is warning that Advanced Persistent Threat (APT) actors are exploiting vulnerabilities in Fortinet FortiOS in ongoing attacks targeting commercial, government, and technology services networks.

The warning, issued in a joint advisory by FBI and the Cybersecurity and Infrastructure Security Agency (CISA), follows the recent release of security patches covering serious security flaws in Fortinet’s flagship FortiOS product.

The two agencies warned that over the past month threat actors have been observed targeting three vulnerabilities in Fortinet FortiOS, namely CVE-2018-13379 (a path traversal vulnerability in the FortiOS SSL VPN web portal), CVE-2020-12812 (FortiOS SSL VPN 2FA bypass), and CVE-2019-5591 (lack of LDAP server identity verification in default configuration).

To date, the observed activity only involved the scanning of devices on ports 4443, 8443, and 10443 for the FortiOS SSL VPN web portal flaw, as well as enumeration of devices potentially vulnerable to the other two security bugs. However, attacks may escalate unexpectedly.

“APT actors have historically exploited critical vulnerabilities to conduct distributed denial-of-service (DDoS) attacks, ransomware attacks, structured query language (SQL) injection attacks, spearphishing campaigns, website defacements, and disinformation campaigns,” according to the advisory.

The two agencies also point out that the recently observed activity surrounding the three Fortinet FortiOS is likely aimed at providing threat actors with access to the networks of commercial, government, and technology services organizations.

“The APT actors may be using any or all of these CVEs to gain access to networks across multiple critical infrastructure sectors to gain access to key networks as pre-positioning for follow-on data exfiltration or data encryption attacks,” CISA and the FBI say.

Additional CVEs and other common exploitation techniques may also be employed in attacks aimed at gaining access to critical infrastructure networks, the two agencies also note.

To stay protected, organizations are advised to immediately apply the available patches for CVE 2018-13379, CVE-2020-12812, and CVE-2019-5591; to keep data backed up; implement network segmentation; restrict software installation to administrator accounts; use multi-factor authentication; disable unused ports; install an antivirus and keep it updated; and keep the operating system up to date as well.

Related: Zerologon Chained With Fortinet, MobileIron Vulnerabilities

Related: Financial Sector Remains Most Targeted by Threat Actors  

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Protection

The CRYSTALS-Kyber public-key encryption and key encapsulation mechanism recommended by NIST for post-quantum cryptography has been broken using AI combined with side channel attacks.

Data Protection

The cryptopocalypse is the point at which quantum computing becomes powerful enough to use Shor’s algorithm to crack PKI encryption.


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Data Breaches

LastPass DevOp engineer's home computer hacked and implanted with keylogging malware as part of a sustained cyberattack that exfiltrated corporate data from the cloud...

Application Security

PayPal is alerting roughly 35,000 individuals that their accounts have been targeted in a credential stuffing campaign.


No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.