Cross-site scripting in Grav CMS

1) Cross-site scripting

EUVDB-ID: #VU20943

Risk: Low

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-5233

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

Exploit availability: No

Description

Vulnerability allows a remote attacker to perform XSS attacks.

The vulnerability is caused by an input validation error in system/src/Grav/Common/Twig/Twig.php when processing data passed via the PATH_INFO parameter to admin/tools URL. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in victim's browser in security 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

Grav CMS: 1.1.0 - 1.2.4

External links

http://www.openwall.com/lists/oss-security/2018/03/15/1
http://sysdream.com/news/lab/2018-03-15-cve-2018-5233-grav-cms-admin-plugin-reflected-cross-site-scripting-xss-vulnerability/

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.