On February 15, in a security notice Canonical published details about OpenJDK vulnerabilities for its Ubuntu 12.10, Ubuntu 12.04 LTS, Ubuntu 11.10, and Ubuntu 10.04 LTS operating systems.
According to Canonical, several security issues have been fixed in OpenJDK. For example, several vulnerabilities have been discovered in the OpenJDK JRE related to information disclosure and data integrity. An attacker could exploit these to cause a denial of service.
Also, a vulnerability was discovered in the OpenJDK JRE related to availability. For a more detailed description of the security problems, you can visit Canonical's security notification.
Users can simply fix the security flaws by upgrading the operating systems to the openjdk-7-jre-lib, openjdk-7-jre-zero, icedtea-7-jre-jamvm, openjdk-7-jre-headless, and openjdk-7-jre specific to each distribution.
A normal system update, executed with the Update Manager, will implement all the necessary changes. After a standard system update, you need to restart any Java applications or applets to make all the necessary changes.