Plone CMS before 3 places a base64 encoded form of the username and password in the __ac cookie for all user accounts, which makes it easier for remote attackers to obtain access by sniffing the network.

References

• https://nvd.nist.gov/vuln/detail/CVE-2008-1394
• https://exchange.xforce.ibmcloud.com/vulnerabilities/41425
• http://securityreason.com/securityalert/3754
• http://www.procheckup.com/Hacking_Plone_CMS.pdf
• http://www.securityfocus.com/archive/1/489544/100/0/threaded
• http://plone.org/about/security/overview/security-overview-of-plone