A vulnerability in how Keystone handles extremely long passwords was discovered. When Keystone is validating a password, glibc allocated space on the stack for the entire password. If the password is long enough, stack space can be exhausted which will lead to a crash. A remote attacker could use this to cause a crash in Keystone by submitting a long password when attempting to log into an existing account; an attacker must know an existing account name to attempt the login with for this attack to be successful.
This flaw is embargoed until 20120327.
Created attachment 571739 [details] preliminary patch to fix the flaw
Hi Vincent. Distro bugs have been created and block this one. Corresponding updates have been pushed. I can't make this public. Can you please? cheers.