firefox crash [@Flash_EnforceLocalSecurity]

Relevant portions of symbolized stacktrack

Stacktrace:
 Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
 Core was generated by `/usr/lib/firefox/firefox-bin'.
 Program terminated with signal 11, Segmentation fault.
 #0 0xffffe410 in __kernel_vsyscall ()
 #0 0xffffe410 in __kernel_vsyscall ()
 #1 0xb7dc7651 in send () from /lib/tls/i686/cmov/libpthread.so.0
 #2 0x0805b2cc in ?? () from /usr/lib/firefox/firefox-bin
 #3 0x0000000b in ?? ()
 #4 0xbf9bdd58 in ?? ()
 #5 0x08057556 in nsProfileLock::FatalSignalHandler (signo=-1210273804) at nsProfileLock.cpp:195
        unblock_sigs = {__val = {3214665632, 3214665652, 3086437447, 3214665632, 3086510120, 6, 3074526280, 1, 0,
     3084637484, 3085678528, 3086508020, 3086509776, 134515524, 3214662816, 3086453058, 3086510200, 3074526280, 1,
     1, 0, 134518837, 89, 0, 134591520, 3084637484, 134591180, 3214662860, 11, 3214662840, 11, 4897}}
        oldact = (sigaction *) 0xb
 #6 0x08057556 in nsProfileLock::FatalSignalHandler (signo=11) at nsProfileLock.cpp:195
        unblock_sigs = {__val = {1024, 0 <repeats 31 times>}}
        oldact = (sigaction *) 0xb
 #7 <signal handler called>
 #8 0xb7dc2404 in pthread_mutex_init () from /lib/tls/i686/cmov/libpthread.so.0
 #9 0xad6f29f8 in NP_Shutdown () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #10 0xad736362 in NP_Shutdown () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #11 0xad600e3d in NP_Shutdown () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #12 0xad574568 in Flash_EnforceLocalSecurity () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #13 0xadbb81c0 in ?? () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #14 0xb7f7dd40 in _dl_close () from /lib/ld-linux.so.2
 #15 0xad56c130 in ?? () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #16 0xadaccc9a in NP_Shutdown () from /usr/lib/flashplugin-nonfree/libflashplayer.so
 #17 0xb7f794ce in _dl_init_internal () from /lib/ld-linux.so.2
 #18 0xb7736299 in clearenv () from /lib/tls/i686/cmov/libc.so.6
 #19 0xb7a35014 in gdk_keymap_get_direction () from /usr/lib/libgdk-x11-2.0.so.0
 #20 0xb7957f4d in _X11TransOpen (type=1, address=0x0) at /usr/include/X11/Xtrans/Xtrans.c:471
        protocol = 0xb7921250 "·\203Çk\215\aOÝÙ/³\220ß4µ\f\021\220F\030}n¿pðc\223@\226@yþü\212\202ø\t\223þE\237¾6ï\222dÝ ,¯À4iH(y\020:|¯Û6\232?îÌß<ZÄòÙðn¨ö÷BâB\216%£SS&\211üP\t§û\207\206\001\016Ûl\177z.BYâS©Ù\233ÇÃY¹]¿\222ôaÓ\034õÉ\027ëP&·6#ÍG g Èõªç£¦öí9½$\027\031ÿ\024\025\203$\026l\003\032\bI­é\202üYÏ¿oéØÛk!^Bù\214{h8\227\201>\237á\2128ß\031òäF«\004\"óT¥\030\033\217®½"...
        host = 0x91c4700 ":0.0"
        port = 0x805d708 "Gecko"
        ciptr = <value optimized out>
        thistrans = (Xtransport *) 0xb77361bb
 #21 0xb7959817 in _XRegisterInternalConnection (dpy=0x91c4130, fd=16711862, callback=0xc600cf,
     call_data=0xff00b6 <Address 0xff00b6 out of bounds>) at ../../src/XlibInt.c:1954
        iptr = <value optimized out>
        watchers = <value optimized out>
        wd = <value optimized out>
 #22 0xb795a7b0 in _XWireToEvent (dpy=0x0, re=0x2, event=0x91c4130) at ../../src/XlibInt.c:2623
 No locals.
 #23 0xb7...

this is a dupe of [@Flash_EnforceLocalSecurity] ... triager will mark accordingly.