Multiple vulnerabilities in Rack

Published: 2018-11-20

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2018-16471 CVE-2018-16470
CWE-ID	CWE-79 CWE-400
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Rack Web applications / Modules and components for CMS
Vendor	Rack

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Cross-site scripting

EUVDB-ID: #VU15970

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-2018-16471

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 escaping of the content returned by the scheme method in the Rack::Request class. 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

The vulnerability has been fixed in the versions 1.6.11, 2.0.6.

Vulnerable software versions

Rack: 0.1 - 2.0.5

External links

http://groups.google.com/forum/#!topic/rubyonrails-security/GKsAFT924Ag

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.

2) Resource exhaustion

EUVDB-ID: #VU15971

Risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-16470

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to resource exhaustion condition in the multipart parser when processing malicious input. A remote attacker can send a custom request, cause the parser to use an excessive amount of CPU resources and cause the service to crash.