This advisory announces multiple security vulnerabilities that were found in Jenkins core.
SECURITY-63 / CVE-2013-2034
This creates a cross-site request forgery (CSRF) vulnerability on Jenkins master, where an anonymous attacker can trick an administrator to execute arbitrary code on Jenkins master by having him open a specifically crafted attack URL.
There's also a related vulnerability where the permission check on this ability is done imprecisely, which may affect those who are running Jenkins instances with a custom authorization strategy plugin.
SECURITY-67 / CVE-2013-2033
SECURITY-69 / CVE-2013-2034
This is another CSRF vulnerability that allows an attacker to cause a deployment of binaries to Maven repositories. This vulnerability has the same CVE ID as SEUCRITY-63.
SECURITY-71 / CVE-2013-1808
This creates a cross-site scripting (XSS) vulnerability.