SB2021080209 - Multiple vulnerabilities in Ruby
Published: August 2, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 secuirty vulnerabilities.
1) Information disclosure (CVE-ID: CVE-2021-31810)
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).
2) Improper Certificate Validation (CVE-ID: CVE-2021-32066)
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists in Net::IMAP in Ruby, due to the gem does not raise an exception when StartTLS fails with an an unknown response. A remote attacker can perform a man-in-the-middle (MitM) attack.
Remediation
Install update from vendor's website.
References
- https://www.ruby-lang.org/en/news/2021/07/07/trusting-pasv-responses-in-net-ftp/
- https://hackerone.com/reports/1145454
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/
- https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a
- https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/
- https://hackerone.com/reports/1178562