private_address_check vulnerable to bypass of Resolv.getaddresses method

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2017-0904: 2.42% estimated exploitation activity in the next 30 days; percentile 84.16 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The privateaddresscheck ruby gem before 0.4.0 is vulnerable to a bypass due to use of Ruby's Resolv.getaddresses method, which is OS-dependent and should not be relied upon for security measures, such as when used to blacklist private network addresses to prevent server-side request forgery.

Published by the source

29 Nov 2017, 23:21 UTC

Last modified by the source

23 Jan 2023, 17:38 UTC

Source last checked

26 Oct 2026, 15:43 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hxhj-hp9m-qwc4

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# Patch Next advisory brief: CVE-2017-0904

Advisory: private_address_check vulnerable to bypass of Resolv.getaddresses method
IDs: CVE-2017-0904, GHSA-hxhj-hp9m-qwc4
Record: https://patchnext.com/advisories/cve-2017-0904 (revision 1, source checked 26 Oct 2026, 15:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: private_address_check 0.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems private_address_check: affected < 0.4.0; fixed in 0.4.0

## Suggested inspection (read-only)
- RubyGems private_address_check: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on private_address_check.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hxhj-hp9m-qwc4 (GitHub-reviewed advisory GHSA-hxhj-hp9m-qwc4 lists affected ranges: RubyGems private_address_check >=0 <0.4.0)

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