Vulnerability identifier: #VU50658

Vulnerability risk: Medium

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-18723

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
MDaemon
Server applications / Mail servers

Vendor: Alt-N

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. The vulnerability allows an attacker to execute code on the email recipient side while forwarding an email to perform potentially malicious activities.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

MDaemon: 19.5.5, 20.0.0

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External links
http://kailashbohara.com.np/blog/2020/07/15/mdaemon-stored-xss
http://packetstormsecurity.com/files/161332/Alt-N-MDaemon-Webmail-20.0.0-Cross-Site-Scripting.html
http://www.altn.com/Support/SecurityUpdate/MD082520_MDaemon_EN/

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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. However, proof of concept for this vulnerability is available.