#VU20192 Cross-site scripting in RubyGems - CVE-2019-8323

Vulnerability identifier: #VU20192

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-8323

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
RubyGems
Universal components / Libraries / Libraries used by multiple products

Vendor: Ruby

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 Gem::GemcutterUtilities#with_response when displaying data in the API. A remote 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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

RubyGems: 2.6.0 - 3.0.1

---

External links
https://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html
https://hackerone.com/reports/315081

---

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.