Multiple vulnerabilities in Ruby

Published: 2021-08-02

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-31810 CVE-2021-32066
CWE-ID	CWE-200 CWE-295
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Ruby Universal components / Libraries / Scripting languages
Vendor	Ruby

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Information disclosure

EUVDB-ID: #VU55488

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-31810

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists within Net::FTP in Ruby when processing PASV responses. A remote attacker can trick the victim to connect to a malicious FTP server and trick Net::FTP into connecting back to a given IP address and port. This potentially makes curl extract information about services that are otherwise private and not disclosed (e.g., the attacker can conduct port scans and service banner extractions).

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Ruby: 2.6.0 - 3.0.1

External links

http://www.ruby-lang.org/en/news/2021/07/07/trusting-pasv-responses-in-net-ftp/
http://hackerone.com/reports/1145454
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/

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) Improper Certificate Validation

EUVDB-ID: #VU55489

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-32066

CWE-ID: CWE-295 - Improper Certificate Validation