#VU20943 Cross-site scripting in Grav CMS - CVE-2018-5233

Vulnerability identifier: #VU20943

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-5233

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Grav CMS
Web applications / CMS

Vendor: Grav CMS

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
https://www.openwall.com/lists/oss-security/2018/03/15/1
https://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.