CVE-2020-12820

Description

Under non-default configuration, a stack-based buffer overflow in FortiOS version 6.0.10 and below, version 5.6.12 and below may allow a remote attacker authenticated to the SSL VPN to crash the FortiClient NAC daemon (fcnacd) and potentially execute arbitrary code via requesting a large FortiClient file name. We are not aware of proof of concept code successfully achieving the latter.

Remediation

Solution:

  • Please upgrade to FortiOS versions 5.6.13 or above. Please upgrade to FortiOS versions 6.0.11 or above. FortiOS versions 6.2.0 and above are not impacted. FortiOS versions 6.4.0 and above are not impacted. Workaround: Please ensure that Fortiheartbeat and Endpoint-Compliance are not both enabled on the same interface. FortiHeartbeat and Endpoint-Compliance can be disabled on a particular interface by following the below CLI commands: config system interface edit interface set endpoint-compliance disable (<-- Disabled by default) set fortiheartbeat disable next end

Categories

5.4
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.24%
Vendor Advisory fortinet.com
Affected: Fortinet FortiOS
Published at:
Updated at:

References

Link Tags
https://fortiguard.fortinet.com/psirt/FG-IR-20-083 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-12820?
CVE-2020-12820 has been scored as a medium severity vulnerability.
How to fix CVE-2020-12820?
To fix CVE-2020-12820: Please upgrade to FortiOS versions 5.6.13 or above. Please upgrade to FortiOS versions 6.0.11 or above. FortiOS versions 6.2.0 and above are not impacted. FortiOS versions 6.4.0 and above are not impacted. Workaround: Please ensure that Fortiheartbeat and Endpoint-Compliance are not both enabled on the same interface. FortiHeartbeat and Endpoint-Compliance can be disabled on a particular interface by following the below CLI commands: config system interface edit interface set endpoint-compliance disable (<-- Disabled by default) set fortiheartbeat disable next end
Is CVE-2020-12820 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2020-12820 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-12820?
CVE-2020-12820 affects Fortinet FortiOS.
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