Drew Yao of the Apple Product Security team reported an integer overflow leading to a memory mis-allocation and heap overflow in the rb_ary_splice() function used by ruby interpreter for handling arrays. Problematic reallocation is: if (len >= RARRAY(ary)->aux.capa) { --> REALLOC_N(RARRAY(ary)->ptr, VALUE, len); RARRAY(ary)->aux.capa = len; } This flaw can be used to crash and possibly execute arbitrary code with the privileges of Ruby application which use untrusted input in array operations. Acknowledgements: Red Hat would like to thank Drew Yao of the Apple Product Security team for reporting this issue.
Created attachment 309637 [details] Drew Yao's proposed patch against ruby 1.8.5
Created attachment 309638 [details] Drew Yao's proposed patch against ruby 1.9
Public now, lifting embargo: http://preview.ruby-lang.org/en/news/2008/06/20/arbitrary-code-execution-vulnerabilities Upstream released fixed versions: 1.8.5-p231, 1.8.6-p230, 1.8.7-p22, 1.9.0-2 Patches applied upstream: http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=17460 http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=17472
BTW there are no rb_ary_splice() function and no such code in even rb_ary_replace() for 1.8.1, we have shipped for RHEL4. however there seems to be similar code in rb_ary_update(). FYI.
ruby-1.8.6.230-1.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report.
ruby-1.8.6.230-1.fc9 has been pushed to the Fedora 9 stable repository. If problems still persist, please make note of it in this bug report.
(In reply to comment #9) So more digging into the issue, it seems REALLOC_N and "beg + rlen" issues existed in ruby forever. Looking at the very first array.c revision in the SVN, it seems to contain predecessor of the current code: http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?annotate=2#l443 It is also present in 1.4.0, thought as "beg + RARRAY(rpl)->len" as of: http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?r1=3&r2=11#l440 This code lived in ary_replace() / rb_ary_replace() in all ruby up to last 1.6.x ruby I managed to find - 1.6.8. ary_replace() -> rb_ary_replace() rename: http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?r1=371&r2=372#l482 Some time in between 1.6.8 and 1.8.0, rb_ary_replace() was renamed to rb_ary_update(): http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?r1=1356&r2=1355&pathrev=1356#l544 This was used in 1.8.0 and 1.8.1. In 1.8.2 function was renamed to current rb_ary_splice(): http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?r1=7306&r2=7305&pathrev=7306#l1074
*** Bug 451835 has been marked as a duplicate of this bug. ***
This issue was addressed in: Red Hat Enterprise Linux: http://rhn.redhat.com/errata/RHSA-2008-0561.html http://rhn.redhat.com/errata/RHSA-2008-0562.html Fedora: https://admin.fedoraproject.org/updates/F8/FEDORA-2008-5649 https://admin.fedoraproject.org/updates/F9/FEDORA-2008-5664