How severe is CVE-2017-17790?

CVE-2017-17790 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-17790 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-17790?

CVE-2017-17790 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-17790?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2017-17790 published?

CVE-2017-17790 was published on 2017-12-20 and last updated on 2026-06-17.

CVE-2017-17790

CVE-2017-17790 is a critical-severity vulnerability in Ruby-lang Ruby with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-74.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 6% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-74
Affected product: Ruby-lang Ruby
Published: 2017-12-20
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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 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.
How severe is CVE-2017-17790?: CVE-2017-17790 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-17790 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-17790?: CVE-2017-17790 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-17790?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-17790 published?: CVE-2017-17790 was published on 2017-12-20 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
cpe:2.3:a:ruby-lang:ruby:2.5.0:preview1:*:*:*:*:*:*

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