CVE-2015-4020
RubyGems 2.0.x before 2.0.17, 2.2.x before 2.2.5, and 2.4.x before 2.4.8 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 with…
Does this matter?
Lower severity and a low EPSS score (3.46%). Track it; it rarely justifies an emergency change on its own.
Description
RubyGems 2.0.x before 2.0.17, 2.2.x before 2.2.5, and 2.4.x before 2.4.8 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 with a domain that is suffixed with the original domain name, aka a "DNS hijack attack." NOTE: this vulnerability exists because to an incomplete fix for CVE-2015-3900.
- CVSS 2.0
- 4.3 MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
- EPSS
- 3.46% probability · 89th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- oracle/solaris · rubygems/rubygems
- Source
- cve@mitre.org
EPSS 3.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://blog.rubygems.org/2015/06/08/2.2.5-released.htmlVendor Advisory
- http://blog.rubygems.org/2015/06/08/2.4.8-released.htmlVendor Advisory
- http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.htmlThird Party Advisory
- http://www.securityfocus.com/bid/75431
- https://github.com/rubygems/rubygems/commit/5c7bfb5
- https://puppet.com/security/cve/CVE-2015-3900
- https://www.trustwave.com/Resources/Security-Advisories/Advisories/TWSL2015-009/?fid=6478Third Party Advisory
- https://www.trustwave.com/Resources/SpiderLabs-Blog/Attacking-Ruby-Gem-Security-with-CVE-2015-3900/Third Party Advisory
- http://blog.rubygems.org/2015/06/08/2.2.5-released.htmlVendor Advisory
- http://blog.rubygems.org/2015/06/08/2.4.8-released.htmlVendor Advisory
- http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.htmlThird Party Advisory
- http://www.securityfocus.com/bid/75431
- https://github.com/rubygems/rubygems/commit/5c7bfb5
- https://puppet.com/security/cve/CVE-2015-3900
- https://www.trustwave.com/Resources/Security-Advisories/Advisories/TWSL2015-009/?fid=6478Third Party Advisory
- https://www.trustwave.com/Resources/SpiderLabs-Blog/Attacking-Ruby-Gem-Security-with-CVE-2015-3900/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.