Plone CMS before 3, places a base64 encoded form of the username and password in the __ac cookie for the admin account, which makes it easier for remote attackers to obtain administrative privileges by sniffing the network.

References

• https://nvd.nist.gov/vuln/detail/CVE-2008-1393
• https://exchange.xforce.ibmcloud.com/vulnerabilities/41427
• http://plone.org/documentation/how-to/secure-login-without-plain-text-passwords
• http://plone.org/products/plone/roadmap/48?
• http://securityreason.com/securityalert/3754
• http://www.procheckup.com/Hacking_Plone_CMS.pdf
• http://www.securityfocus.com/archive/1/489544/100/0/threaded