Vulnerability identifier: #VU49153

Vulnerability risk: High

CVSSv3.1: 5.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:H/RL:O/RC:C]

CVE-ID: CVE-2020-35730

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Roundcube
Web applications / Webmail solutions

Vendor: Roundcube

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. A remote attacker can send a specially crafted email message in HTML or plain text and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

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 updates from vendor's website.

Vulnerable software versions

Roundcube: 1.4.0 - 1.4.9, 1.3.0 - 1.3.15, 1.2.0 - 1.2.12

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External links
http://github.com/roundcube/roundcubemail/releases/tag/1.4.10
http://www.recordedfuture.com/bluedelta-exploits-ukrainian-government-roundcube-mail-servers

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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.