A security vulnerability was recently discovered that would allow a malicious person to delete the contents of a history that does not belong to them. The vulnerability was in a method designed to allow users to switch between histories as a convenience from certain messages and is not used for most normal history switching operations. A fix has been provided in the stable branch of the Galaxy distribution and tagged as security_2013.04.08. Administrators are strongly encouraged to upgrade to at least the listed tag or to implement one of the provided workarounds. This changeset is not included in the most recent (April 1, 2013) stable release.
Additional details, including workarounds for those who are unable or unwilling to perform a full upgrade, can be found in the mailing list announcement.
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