Multiple vulnerabilities have been discovered in the Ruby interpreter and its standard libraries. Drew Yao of Apple Product Security discovered the following flaws:

• Arbitrary code execution or Denial of Service (memory corruption) in the rb_str_buf_append() function (CVE-2008-2662).
• Arbitrary code execution or Denial of Service (memory corruption) in the rb_ary_stor() function (CVE-2008-2663).
• Memory corruption via alloca in the rb_str_format() function (CVE-2008-2664).
• Memory corruption ("REALLOC_N") in the rb_ary_splice() and rb_ary_replace() functions (CVE-2008-2725).
• Memory corruption ("beg + rlen") in the rb_ary_splice() and rb_ary_replace() functions (CVE-2008-2726).

Furthermore, several other vulnerabilities have been reported:

• Tanaka Akira reported an issue with resolv.rb that enables attackers to spoof DNS responses (CVE-2008-1447).
• Akira Tagoh of RedHat discovered a Denial of Service (crash) issue in the rb_ary_fill() function in array.c (CVE-2008-2376).
• Several safe level bypass vulnerabilities were discovered and reported by Keita Yamaguchi (CVE-2008-3655).
• Christian Neukirchen is credited for discovering a Denial of Service (CPU consumption) attack in the WEBRick HTTP server (CVE-2008-3656).
• A fault in the dl module allowed the circumvention of taintness checks which could possibly lead to insecure code execution was reported by "sheepman" (CVE-2008-3657).
• Tanaka Akira again found a DNS spoofing vulnerability caused by the resolv.rb implementation using poor randomness (CVE-2008-3905).
• Luka Treiber and Mitja Kolsek (ACROS Security) disclosed a Denial of Service (CPU consumption) vulnerability in the REXML module when dealing with recursive entity expansion (CVE-2008-3790).