Stored cross-site scripting in Jenkins Markdown Formatter plugin

1) Stored cross-site scripting

EUVDB-ID: #VU53591

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21660

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. A remote authenticated 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 updates from vendor's website.

Vulnerable software versions

Markdown Formatter: 0.1.0

External links

http://www.jenkins.io/security/advisory/2021-05-25/#SECURITY-2198
http://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-21660
http://www.openwall.com/lists/oss-security/2021/05/25/3

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.