(RHSA-2011:0908) Moderate: ruby security update

Ruby is an extensible, interpreted, object-oriented, scripting language. It
has features to process text files and to do system management tasks.

A flaw was found in the way large amounts of memory were allocated on
64-bit systems when using the BigDecimal class. A context-dependent
attacker could use this flaw to cause memory corruption, causing a Ruby
application that uses the BigDecimal class to crash or, possibly, execute
arbitrary code. This issue did not affect 32-bit systems. (CVE-2011-0188)

It was found that WEBrick (the Ruby HTTP server toolkit) did not filter
terminal escape sequences from its log files. A remote attacker could use
specially-crafted HTTP requests to inject terminal escape sequences into
the WEBrick log files. If a victim viewed the log files with a terminal
emulator, it could result in control characters being executed with the
privileges of that user. (CVE-2009-4492)

A cross-site scripting (XSS) flaw was found in the way WEBrick displayed
error pages. A remote attacker could use this flaw to perform a cross-site
scripting attack against victims by tricking them into visiting a
specially-crafted URL. (CVE-2010-0541)

A flaw was found in the method for translating an exception message into a
string in the Exception class. A remote attacker could use this flaw to
bypass safe level 4 restrictions, allowing untrusted (tainted) code to
modify arbitrary, trusted (untainted) strings, which safe level 4
restrictions would otherwise prevent. (CVE-2011-1005)

Red Hat would like to thank Drew Yao of Apple Product Security for
reporting the CVE-2011-0188 and CVE-2010-0541 issues.

All Ruby users should upgrade to these updated packages, which contain
backported patches to resolve these issues.