Cross-site scripting in Subscribe Sidebar plugin by Blubrry for WordPress

1) Cross-site scripting

EUVDB-ID: #VU46142

Risk: Low

CVSSv3.1: 5.1 [CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N/E:P/RL:U/RC:C]

CVE-ID: CVE-2020-25033

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 passed via the "status" GET parameter in "subscribe_sidebar.php" file. A remote authenticated 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.

PoC:

/wp-admin/options-general.php?page=subscribe_sidebar.php&status=%3Cscript%3Ealert%28document.cookie%29%3C%2Fscript%3E

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Subscribe Sidebar plugin by Blubrry: 1.0 - 1.3.1

External links

http://wordpress.org/plugins/subscribe-sidebar/#developers
http://zeroaptitude.com/pitticus/subscribe-sidebar-plugin-by-blubrry-v1-3-1-reflected-xss-20-jun-2020/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.