Multiple vulnerabilities have been discovered in Ruby that allow for
attacks including arbitrary code execution and Denial of Service.
Background
Ruby is an interpreted object-oriented programming language. The
elaborate standard library includes an HTTP server ("WEBRick") and a
class for XML parsing ("REXML").
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).
Impact
These vulnerabilities allow remote attackers to execute arbitrary code,
spoof DNS responses, bypass Ruby's built-in security and taintness
checks, and cause a Denial of Service via crash or CPU exhaustion.
Workaround
There is no known workaround at this time.
Resolution
All Ruby users should upgrade to the latest version:
Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.