It was found that various OpenID Providers (OPs) had TLS Server Certificates that used weak keys, as a result of the Debian Predictable Random Number Generator (CVE-2008-0166). In combination with the DNS Cache Poisoning issue (CVE-2008-1447) and the fact that almost all SSL/TLS implementations do not consult CRLs (currently an untracked issue), this means that it is impossible to rely on these OPs.

References

• https://nvd.nist.gov/vuln/detail/CVE-2008-3280
• https://www.exploit-db.com/exploits/5720
• http://lists.openid.net/pipermail/openid-security/2008-August/000942.html