---
library: rubygems
cve: 2015-4020
url: https://www.trustwave.com/Resources/Security-Advisories/Advisories/TWSL2015-009/?fid=6478
title: |
  RubyGems remote_fetcher.rb api_endpoint() Function Missing SRV Record
  Hostname Validation Request Hijacking
date: 2015-06-08
description: |
  RubyGems contains a flaw in the api_endpoint() function in remote_fetcher.rb
  that is triggered when handling hostnames in SRV records. With a specially
  crafted response, a context-dependent attacker may conduct DNS hijacking
  attacks. This vulnerability is due to an incomplete fix for CVE-2015-3900,
  which allowed redirection to an arbitrary gem server in any security domain. 
cvss_v2: 5.0
patched_versions:
  - ~> 2.0.17
  - ~> 2.2.5
  - ">= 2.4.8"