Stored cross-site scripting in Plone

1) Stored cross-site scripting

EUVDB-ID: #VU53648

Risk: Low

CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3313

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

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 the user fullname property and the file upload functionality. A remote attacker can inject 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 update from vendor's website.

Vulnerable software versions

Plone: 5.2.1 - 5.2.2

External links

http://www.compass-security.com/fileadmin/Research/Advisories/2021-07_CSNC-2021-013_XSS_in_Plone_CMS.txt
http://plone.org/download/releases/5.2.3
http://plone.org/security/hotfix/20210518
http://www.openwall.com/lists/oss-security/2021/05/22/1

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.