Secunia

Some vulnerabilities have been reported in Ruby, which can be exploited by malicious people to disclose sensitive information, cause a DoS (Denial of Service), or potentially compromise a vulnerable system.

1) Input passed via the URL to applications using "WEBrick::HTTPServlet::FileHandler" or "WEBrick::HTTPServer.new" with the ":DocumentRoot" option is not properly sanitised before being used. This can be exploited to disclose the content of files via a URL with certain characters appended (e.g. "+", "%2b", ".", "%2e", and "%20").

This is related to:
SA29232

Successful exploitation requires that a certain file system is used, e.g. NTFS or FAT32.

2) Multiple integer overflow errors exist within the "ary_new()", "rb_ary_initialize()", "rb_ary_store()", "rb_ary_times()", and "rb_ary_splice()" functions in array.c. These can potentially be exploited to cause buffer overflows via overly large arguments passed to the affected functions.

3) An error when allocating memory via an improper call to "alloca()" in "rb_str_buf_append()" can be exploited to corrupt memory.

Successful exploitation of the vulnerabilities may allow execution of arbitrary code.

The vulnerabilities are reported in the following versions:
* 1.8.4 and prior
* 1.8.5-p230 and prior
* 1.8.6-p229 and prior
* 1.8.7-p21 and prior

Solution
Update to a fixed version.
Further details available in Customer Area

Provided and/or discovered by
1) Luigi Auriemma
2, 3) The vendor credits Drew Yao of Apple Product Security.

Changelog
Further details available in Customer Area

Original Advisory
1) http://aluigi.altervista.org/adv/webrickcgi-adv.txt
2, 3) http://www.ruby-lang.org/en/news/2008/06/20/arbitrary-code-execution-vulnerabilities/

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area