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."

Published: 2015-06-24 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-3900 is rated Moderate Risk (58.1/100): CVSS Medium severity, with high exploitation likelihood (EPSS 8.93%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +6.53% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-3900

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.40% 8.93% +6.53%
2 2026-03-04 4.03% 2.40% -1.63%
3 2026-03-01 — 4.03% —

Full EPSS history (41 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-3900

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2015-3900

GitHub Security Advisory for CVE-2015-3900

GHSA-wp3j-rvfp-624h · Severity: high · Ecosystem: rubygems — RubyGems vulnerable to DNS hijack attack

OS Trackers for CVE-2015-3900

vendor priority summary link
debian unimportant CVE-2015-3900 unimportant priority: Debian including 2 source packages (jruby, rubygems), 9 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 9. https://security-tracker.debian.org/tracker/CVE-2015-3900
redhat high — https://access.redhat.com/security/cve/CVE-2015-3900
suse medium CVE-2015-3900 severity moderate: SUSE including 39 source package names (4.0.0:libruby2_1-2_1-2.1.9-15.1, 4.0.0:ruby2.1-2.1.9-15.1, …), 306 product×package rows across 83 product lines (Container caasp/v4/velum, HPE Helion OpenStack 8, … (83 product lines)): Known Not Affected 180, Fixed 126. https://www.suse.com/security/cve/CVE-2015-3900/
ubuntu low CVE-2015-3900 low priority: Ubuntu including 8 source packages (jruby, libgems-ruby, …), 48 status rows across 6 suites (precise, trusty, upstream, utopic, vivid, wily): DNE 26, not-affected 16, released 3, ignored 2, needs-triage 1. https://ubuntu.com/security/CVE-2015-3900

Affected software / configurations for CVE-2015-3900

Vendor Product Version Raw CPE
ruby-lang ruby 1.9 cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:*:*:*:*:*:*:*
ruby-lang ruby 1.9.2 cpe:2.3:a:ruby-lang:ruby:1.9.2:*:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:*:*:*:*:*:*:*
ruby-lang ruby 2.0.0 cpe:2.3:a:ruby-lang:ruby:2.0.0:*:*:*:*:*:*:*
ruby-lang ruby 2.1 cpe:2.3:a:ruby-lang:ruby:2.1:-:*:*:*:*:*:*
ruby-lang ruby 2.1.1 cpe:2.3:a:ruby-lang:ruby:2.1.1:*:*:*:*:*:*:*
ruby-lang ruby 2.1.2 cpe:2.3:a:ruby-lang:ruby:2.1.2:*:*:*:*:*:*:*
ruby-lang ruby 2.1.3 cpe:2.3:a:ruby-lang:ruby:2.1.3:*:*:*:*:*:*:*
ruby-lang ruby 2.1.4 cpe:2.3:a:ruby-lang:ruby:2.1.4:*:*:*:*:*:*:*
ruby-lang ruby 2.1.5 cpe:2.3:a:ruby-lang:ruby:2.1.5:*:*:*:*:*:*:*
ruby-lang ruby 2.2.0 cpe:2.3:a:ruby-lang:ruby:2.2.0:*:*:*:*:*:*:*
rubygems rubygems 2.0.0 cpe:2.3:a:rubygems:rubygems:2.0.0:*:*:*:*:*:*:*
rubygems rubygems 2.0.1 cpe:2.3:a:rubygems:rubygems:2.0.1:*:*:*:*:*:*:*
rubygems rubygems 2.0.2 cpe:2.3:a:rubygems:rubygems:2.0.2:*:*:*:*:*:*:*
rubygems rubygems 2.0.3 cpe:2.3:a:rubygems:rubygems:2.0.3:*:*:*:*:*:*:*
rubygems rubygems 2.0.4 cpe:2.3:a:rubygems:rubygems:2.0.4:*:*:*:*:*:*:*
rubygems rubygems 2.0.5 cpe:2.3:a:rubygems:rubygems:2.0.5:*:*:*:*:*:*:*
rubygems rubygems 2.0.6 cpe:2.3:a:rubygems:rubygems:2.0.6:*:*:*:*:*:*:*
rubygems rubygems 2.0.7 cpe:2.3:a:rubygems:rubygems:2.0.7:*:*:*:*:*:*:*
rubygems rubygems 2.0.8 cpe:2.3:a:rubygems:rubygems:2.0.8:*:*:*:*:*:*:*
rubygems rubygems 2.0.9 cpe:2.3:a:rubygems:rubygems:2.0.9:*:*:*:*:*:*:*
rubygems rubygems 2.0.10 cpe:2.3:a:rubygems:rubygems:2.0.10:*:*:*:*:*:*:*
rubygems rubygems 2.0.11 cpe:2.3:a:rubygems:rubygems:2.0.11:*:*:*:*:*:*:*
rubygems rubygems 2.0.12 cpe:2.3:a:rubygems:rubygems:2.0.12:*:*:*:*:*:*:*
rubygems rubygems 2.0.13 cpe:2.3:a:rubygems:rubygems:2.0.13:*:*:*:*:*:*:*
rubygems rubygems 2.0.14 cpe:2.3:a:rubygems:rubygems:2.0.14:*:*:*:*:*:*:*
rubygems rubygems 2.0.15 cpe:2.3:a:rubygems:rubygems:2.0.15:*:*:*:*:*:*:*
rubygems rubygems 2.2.0 cpe:2.3:a:rubygems:rubygems:2.2.0:*:*:*:*:*:*:*
rubygems rubygems 2.2.1 cpe:2.3:a:rubygems:rubygems:2.2.1:*:*:*:*:*:*:*
rubygems rubygems 2.2.2 cpe:2.3:a:rubygems:rubygems:2.2.2:*:*:*:*:*:*:*
rubygems rubygems 2.2.3 cpe:2.3:a:rubygems:rubygems:2.2.3:*:*:*:*:*:*:*
rubygems rubygems 2.4.0 cpe:2.3:a:rubygems:rubygems:2.4.0:*:*:*:*:*:*:*
rubygems rubygems 2.4.1 cpe:2.3:a:rubygems:rubygems:2.4.1:*:*:*:*:*:*:*
rubygems rubygems 2.4.2 cpe:2.3:a:rubygems:rubygems:2.4.2:*:*:*:*:*:*:*
rubygems rubygems 2.4.3 cpe:2.3:a:rubygems:rubygems:2.4.3:*:*:*:*:*:*:*
rubygems rubygems 2.4.4 cpe:2.3:a:rubygems:rubygems:2.4.4:*:*:*:*:*:*:*
rubygems rubygems 2.4.5 cpe:2.3:a:rubygems:rubygems:2.4.5:*:*:*:*:*:*:*
rubygems rubygems 2.4.6 cpe:2.3:a:rubygems:rubygems:2.4.6:*:*:*:*:*:*:*
oracle solaris 11.3 cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*

References for CVE-2015-3900

URL Tags
http://blog.rubygems.org/2015/05/14/CVE-2015-3900.html Patch Vendor Advisory
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 Third Party Advisory
http://www.openwall.com/lists/oss-security/2015/06/26/2 Third Party Advisory
http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html Third Party Advisory
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 Third Party Advisory
https://www.trustwave.com/Resources/SpiderLabs-Blog/Attacking-Ruby-Gem-Security-with-CVE-2015-3900/ Third Party Advisory
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