Red Hat Security Advisory 2014-1436-02 - The X11 libraries provide library routines that are used within all X Window applications. Multiple integer overflow flaws, leading to heap-based buffer overflows, were found in the way various X11 client libraries handled certain protocol data. An attacker able to submit invalid protocol data to an X11 server via a malicious X11 client could use either of these flaws to potentially escalate their privileges on the system.
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