#VU52377 Path traversal

Published: 2021-04-20 | Updated: 2021-04-21

Vulnerability identifier: #VU52377

Vulnerability risk: High

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-20023


Exploitation vector: Network

Exploit availability: No

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



The vulnerability allows a remote user to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences within the "branding"  feature. A remote authenticated user can send a specially crafted HTTP request and read arbitrary files on the system with NT AUTHORITY\SYSTEM account.

Request example:

https://<SonicWall ES host>/dload_apps?action=<any value>&path=..%2F..%2F..%2F..%2F..%2Fwindows%2Fsystem32%2Fcalc.exe&id=update

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

Install update from vendor's website.

Vulnerable software versions

External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

Latest bulletins with this vulnerability