CVE-2021-31810

Published: 13 July 2021

An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. A malicious FTP server can use the PASV response to 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).

Notes

for xenial, the backport can be kind of intrusive. for now ignoring it.

Status

Severity score breakdown

References

• https://www.ruby-lang.org/en/news/2021/07/07/trusting-pasv-responses-in-net-ftp/
• https://github.com/ruby/ruby/commit/3ca1399150ed4eacfd2fe1ee251b966f8d1ee469 (2.7)
• https://hackerone.com/reports/1145454
• https://ubuntu.com/security/notices/USN-5020-1
• https://www.cve.org/CVERecord?id=CVE-2021-31810
• NVD
• Launchpad
• Debian