Multiple vulnerabilities in SonicWall On-premise Email Security (ES) and Hosted Email Security (HES)

Published: 2021-04-12 | Updated: 2021-04-21

Risk	Critical
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-20021 CVE-2021-20022
CWE-ID	CWE-287 CWE-434
Exploitation vector	Network
Public exploit	Vulnerability #1 is being exploited in the wild. Vulnerability #2 is being exploited in the wild.
Vulnerable software	SonicWall On-premise Email Security (ES) Client/Desktop applications / Antivirus software/Personal firewalls SonicWall Hosted Email Security (HES) Client/Desktop applications / Antivirus software/Personal firewalls
Vendor	SonicWall

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

Updated: 21.04.2021

Updated vulnerabilities description, related to in the wild exploitation of the vulnerabilities as well as information, disclosed by FireEye. Raised severity level of the bulletin from High to Critical.

1) Improper Authentication

EUVDB-ID: #VU52038

Risk: Critical

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: CVE-2021-20021

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in when processing authentication requests within the "/createou?data=", responsible for administration capabilities, specifically within the feature that allows application administrators to authorize an additional administrator account from a separate Microsoft Active Directory Organization Unit (AD OU). Requests to this form are not verified to require previous authentication to the appliance. A remote non-authenticated attacker can send a specially crafted XML document via HTTP GET or POST method, create a “role.ouadmin” account and authenticate to the application as an administrator.

Note, the vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

SonicWall On-premise Email Security (ES): before 10.0.9.6103

SonicWall Hosted Email Security (HES): before 10.0.9.6103

CPE2.3

External links

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007
https://www.fireeye.com/blog/threat-research/2021/04/zero-day-exploits-in-sonicwall-email-security-lead-to-compromise.html

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?

Yes. This vulnerability is being exploited in the wild.

2) Arbitrary file upload

EUVDB-ID: #VU52039

Risk: High

CVSSv4.0: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2021-20022

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type