#VU67805 Cross-site scripting in Sophos Firewall - CVE-2021-25267

Vulnerability identifier: #VU67805

Vulnerability risk: Medium

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-25267

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Sophos Firewall
Hardware solutions / Security hardware applicances

Vendor: Sophos

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 in Webadmin. A remote attacker can trick the victim to follow a specially crafted link 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

Sophos Firewall: 18.5.0 - 18.5.3

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External links
https://www.sophos.com/en-us/security-advisories/sophos-sa-20220907-sfos-18-5-4

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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.