CVE-2017-0909: The private_address_check ruby gem before 0.4.1 is vulnerable to a bypass due to an incomplete blacklist of co

Q: How do I fix CVE-2017-0909?

private address check: upgrade to 0.4.1. Exact commands for each OS are on this page.

Q: Is CVE-2017-0909 being exploited?

CVE-2017-0909 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2017-0909 affect?

CVE-2017-0909 affects private address check. Severity is critical (CVSS 9.8). The private_address_check ruby gem before 0.4.1 is vulnerable to a bypass due to an incomplete blacklist of common private/local network addresses used to prevent server-side request forgery.

Q: How urgent is CVE-2017-0909?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2017-0909 is a critical-severity flaw (CVSS 9.8) affecting private address check. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The private_address_check ruby gem before 0.4.1 is vulnerable to a bypass due to an incomplete blacklist of common private/local network addresses used to prevent server-side request forgery.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-184
Published	2017-11-16
Last modified	2026-06-17

Publisher (CNA): HackerOne · Vendor: private address check project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-11-16 22:29 UTCPublished CVE record published
2026-06-17 00:58 UTCUpdated Record last modified

private address check project private address check UPGRADE

Affected: < 0.4.1

Fixed in: 0.4.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy private-address-check || rpm -q private-address-check || private-address-check --version

2. UPGRADE to 0.4.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade private-address-check

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade private-address-check

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2017-0909?

private address check: upgrade to 0.4.1. Exact commands for each OS are on this page.

Is CVE-2017-0909 being exploited?

CVE-2017-0909 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2017-0909 affect?

CVE-2017-0909 affects private address check. Severity is critical (CVSS 9.8). The private_address_check ruby gem before 0.4.1 is vulnerable to a bypass due to an incomplete blacklist of common private/local network addresses used to prevent server-side request forgery.

How urgent is CVE-2017-0909?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Ruby vulnerabilities

Related CVEs

CVE-2018-3759 LOW 3.7 UPGRADE private_address_check ruby gem before 0.5.0 is vulnerable to a time-of-check time-of-use (TOCTOU) race conditi
CVE-2017-0904 HIGH 8.1 UPGRADE The private_address_check ruby gem before 0.4.0 is vulnerable to a bypass due to use of Ruby's Resolv.getaddre

References

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