What’s Vulnerable › Vulnerabilities
CVE-2021-31810
- Severity: medium (CVSS 5.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 3.0% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2021-07-13 · updated 2026-06-17
Description
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).
Affected products
- Debian Linux: 9.0
- Oracle Corporation JD Edwards EnterpriseOne Tools: before 9.2.6.1 — fixed in 9.2.6.1
- Ruby: through 2.6.7; from 2.7.0 through 2.7.3; from 3.0.0 through 3.0.1
How to fix
Upgrade to a fixed version: Oracle Corporation JD Edwards EnterpriseOne Tools 9.2.6.1. Check the vendor advisory for mitigations.
References
- https://hackerone.com/reports/1145454
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.html
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20210917-0001/
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.ruby-lang.org/en/news/2021/07/07/trusting-pasv-responses-in-net-ftp/
- https://hackerone.com/reports/1145454
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.html
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MWXHK5UUHVSHF7HTHMX6JY3WXDVNIHSL/
Get alerted when CVE-2021-31810 or the next vulnerability affects your stack