Vulnerability identifier: #VU48651

Vulnerability risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28724

CWE-ID: CWE-601

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Werkzeug
Web applications / JS libraries

Vendor: The Pallets Projects

Description

The vulnerability allows a remote attacker to redirect victims to arbitrary URL.

The vulnerability exists due to improper sanitization of user-supplied data within the double slash in the URL. A remote attacker can create a link that leads to a trusted website, however, when clicked, redirects the victim to arbitrary domain.

Successful exploitation of this vulnerability may allow a remote attacker to perform a phishing attack and steal potentially sensitive information.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Werkzeug: 0.11 - 0.11.5

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External links
http://github.com/pallets/flask/issues/1639
http://github.com/pallets/werkzeug/issues/822
http://github.com/pallets/werkzeug/pull/890/files

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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.