RubyGems: Specially-crafted Gem archive can overwrite system files

The extract_files function in installer.rb in RubyGems before 0.9.1 does not check whether files exist before overwriting them, which allows user-assisted remote attackers to overwrite arbitrary files, cause a denial of service, or execute arbitrary code via crafted GEM packages.

The sqlite3-ruby gem in the rubygem-sqlite3 package before 1.2.4-0.5.1 in SUSE Linux Enterprise (SLE) 11 SP1 uses weak permissions for unspecified files, which allows local users to gain privileges via unknown vectors.