CVE-2015-3900

CVE-2015-3900 is a medium-severity vulnerability in Ruby-lang Ruby with a CVSS 2.0 base score of 5.0. 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-254.

Key facts

• Severity: Medium (CVSS 2.0 base score 5.0)
• EPSS exploit prediction: 9% (95th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-254
• Affected product: Ruby-lang Ruby
• Published: 2015-06-24
• Last modified: 2026-06-17

Description

RubyGems 2.0.x before 2.0.16, 2.2.x before 2.2.4, and 2.4.x before 2.4.7 does not validate the hostname when fetching gems or making API requests, which allows remote attackers to redirect requests to arbitrary domains via a crafted DNS SRV record, aka a "DNS hijack attack."

Frequently asked questions

What is CVE-2015-3900?

RubyGems 2.0.x before 2.0.16, 2.2.x before 2.2.4, and 2.4.x before 2.4.7 does not validate the hostname when fetching gems or making API requests, which allows remote attackers to redirect requests to arbitrary domains via a crafted DNS SRV record, aka a "DNS hijack attack."

How severe is CVE-2015-3900?

CVE-2015-3900 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2015-3900 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-3900?

CVE-2015-3900 primarily affects Ruby-lang Ruby. In total, 42 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-3900?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-3900 published?

CVE-2015-3900 was published on 2015-06-24 and last updated on 2026-06-17.

References

• http://blog.rubygems.org/2015/05/14/CVE-2015-3900.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-August/163502.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-August/163600.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-August/164236.html
• http://rhn.redhat.com/errata/RHSA-2015-1657.html
• http://www.openwall.com/lists/oss-security/2015/06/26/2
• http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
• http://www.securityfocus.com/bid/75482
• https://puppet.com/security/cve/CVE-2015-3900
• https://www.trustwave.com/Resources/Security-Advisories/Advisories/TWSL2015-007/?fid=6356
• https://www.trustwave.com/Resources/SpiderLabs-Blog/Attacking-Ruby-Gem-Security-with-CVE-2015-3900/

Affected products (42)

• cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:1.9.1:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:1.9.2:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:1.9.3:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1:-:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1.1:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1.2:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1.3:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1.4:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.1.5:*:*:*:*:*:*:*
• cpe:2.3:a:ruby-lang:ruby:2.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.9:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.11:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.12:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.13:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.14:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.0.15:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.2.2:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.2.3:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.0:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.1:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.2:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.3:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.4:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.5:*:*:*:*:*:*:*
• cpe:2.3:a:rubygems:rubygems:2.4.6:*:*:*:*:*:*:*
• cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*

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