Vulnerability identifier: #VU60931

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15936

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FortiOS
Operating systems & Components / Operating system

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the system via SNI Client Hello TLS packets. A remote attacker can send a specially crafted request to the system and gain access to sensitive information.

Mitigation

Given that there is no systematic way to detect all exfiltration attempts and to exhaustively enumerate all possibilities offered by exfiltration channels, Fortinet has addressed the issue by releasing a set of signatures:

1. Python/SNICat.A!exploit
   https://www.fortiguard.com/encyclopedia/virus/10069638

2. SNIcat.Data.Exfiltration.Tool
   https://www.fortiguard.com/encyclopedia/ips/50952

Vulnerable software versions

FortiOS: 6.4.0 - 6.4.3, 6.2.0 - 6.2.5, 6.0.0 - 6.0.11

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External links
http://fortiguard.com/advisory/FG-IR-20-091

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.