Debian Linux Security Advisory 3438-1 - It was discovered that unplugging one of the monitors in a multi-monitor setup can cause xscreensaver to crash. Someone with physical access to a machine could use this problem to bypass a locked session.
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Ubuntu Security Notice 2789-1 - It was discovered that XScreenSaver incorrectly handled unplugging an external monitor. An attacker with physical access could use this flaw to gain access to a locked session.
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