#VU96748 Path traversal in VigorConnect - CVE-2021-20123

Vulnerability identifier: #VU96748

Vulnerability risk: High

CVSSv4.0: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2021-20123

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
VigorConnect
Server applications / Remote management servers, RDP, SSH

Vendor: DrayTek Corp.

Description

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

The vulnerability exists due to input validation error when processing directory traversal sequences in the file download functionality of the DownloadFileServlet endpoint. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

VigorConnect: 1.1.0 - 1.6.0

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External links
https://www.tenable.com/security/research/tra-2021-42

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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?

Yes. This vulnerability is being exploited in the wild.