Vulnerability identifier: #VU59664

Vulnerability risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-45087

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
GNOME Web (Epiphany)
Client/Desktop applications / Web browsers

Vendor: Gnome Development Team

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 when View Source mode or Reader mode is used. A remote attacker can 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

GNOME Web (Epiphany): 41.0, 40.0 - 40.3

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External links
http://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/1045
http://gitlab.gnome.org/GNOME/epiphany/-/issues/1612
http://www.debian.org/security/2022/dsa-5042

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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.