CVE-2011-2705

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2011-08-05 · updated 2026-06-16
Weakness: CWE-20

Description

The SecureRandom.random_bytes function in lib/securerandom.rb in Ruby before 1.8.7-p352 and 1.9.x before 1.9.2-p290 relies on PID values for initialization, which makes it easier for context-dependent attackers to predict the result string by leveraging knowledge of random strings obtained in an earlier process with the same PID.

Affected products

Ruby: through 1.8.7-334; 1.8.7-p22, 1.8.7-p71, 1.8.7-p72, 1.8.7-160, 1.8.7-173, 1.8.7-248 (+28)

References

http://lists.fedoraproject.org/pipermail/package-announce/2011-July/063062.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-July/063071.html
http://redmine.ruby-lang.org/issues/4579
http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=32050
http://svn.ruby-lang.org/repos/ruby/tags/v1_8_7_352/ChangeLog
http://svn.ruby-lang.org/repos/ruby/tags/v1_9_2_290/ChangeLog
http://www.openwall.com/lists/oss-security/2011/07/11/1
http://www.openwall.com/lists/oss-security/2011/07/12/14
http://www.openwall.com/lists/oss-security/2011/07/20/1
http://www.openwall.com/lists/oss-security/2011/07/20/16
http://www.redhat.com/support/errata/RHSA-2011-1581.html
http://www.ruby-lang.org/en/news/2011/07/02/ruby-1-8-7-p352-released/

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