A security problem involving peer certificate verification was found where failed verification silently did nothing, making affected applications vulnerable to attackers. Attackers could lead a client application to believe that a secure connection to a rogue SSL server is legitimate. Attackers could also penetrate client-validated SSL server applications with a dummy certificate.

References

• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/jruby-openssl/CVE-2009-4123.yml
• http://jruby.org/2009/12/07/vulnerability-in-jruby-openssl
• https://nvd.nist.gov/vuln/detail/CVE-2009-4123
• GHSA-xgv7-pqqh-h2w9
• https://web.archive.org/web/20101213091125/http://jruby.org/2009/12/07/vulnerability-in-jruby-openssl