Bug 1484287

Created attachment 1316980 [details]
Triggered by "  ./captoinfo POC11  "

Description of problem:

There is an illegal address access in function dump_uses() of libncurses.

Version-Release number of selected component (if applicable):

<= latest version

How reproducible:

./captoinfo POC11  

Steps to Reproduce:

$ ./../../../captoinfo POC11  
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 2, col 605, terminal 'a': Very long string found.  Missing separator?
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': Illegal character - '^J'
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': Legacy termcap allows only a trailing tc= clause
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': unknown capability 'k'
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 14, col 5, terminal 'a': Missing separator
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 14, col 7, terminal 'a': Illegal character (expected alphanumeric or @%&*!#) - 'M-4'
Segmentation fault

The GDB debugging information is as follows:
(gdb) set args POC5
(gdb) r
Starting program: /home/icy/secreal/ncurses-6.0-20170819/install/bin/captoinfo id:000147,sig:11,src:001048,op:havoc,rep:2
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 2, col 605, terminal 'a': Very long string found.  Missing separator?
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': Illegal character - '^J'
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': Legacy termcap allows only a trailing tc= clause
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 13, col 7, terminal 'a': unknown capability 'k'
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 14, col 5, terminal 'a': Missing separator
"id:000147,sig:11,src:001048,op:havoc,rep:2", line 14, col 7, terminal 'a': Illegal character (expected alphanumeric or @%&*!#) - 'M-4'

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7a5d462 in _IO_vfprintf_internal (s=s@entry=0x7fffffffa160, format=<optimized out>, 
    format@entry=0x459f57 "%s%s", ap=ap@entry=0x7fffffffa288) at vfprintf.c:1642
1642	vfprintf.c: No such file or directory.
(gdb) bt 
#0  0x00007ffff7a5d462 in _IO_vfprintf_internal (s=s@entry=0x7fffffffa160, format=<optimized out>, 
    format@entry=0x459f57 "%s%s", ap=ap@entry=0x7fffffffa288) at vfprintf.c:1642
#1  0x00007ffff7a804eb in __IO_vsprintf (string=0x7fffffffa360 "use=\204", '\264' <repeats 195 times>..., 
    format=0x459f57 "%s%s", args=args@entry=0x7fffffffa288) at iovsprintf.c:42
#2  0x00007ffff7a63d17 in __sprintf (s=<optimized out>, format=<optimized out>) at sprintf.c:32
#3  0x000000000041a732 in dump_uses (
    name=0xb4b4b4b4b4b4b4b4 <error: Cannot access memory at address 0xb4b4b4b4b4b4b4b4>, infodump=<optimized out>)
    at ../progs/dump_entry.c:1618
#4  0x0000000000403ee3 in main (argc=<optimized out>, argv=<optimized out>) at ../progs/tic.c:1035
(gdb) 

Trigged in:
dump_uses (name=0xb4b4b4b4b4b4b4b4 <error: Cannot access memory at address 0xb4b4b4b4b4b4b4b4>, 
    infodump=true) at ../progs/dump_entry.c:1618
1618	    _nc_SPRINTF(buffer, _nc_SLIMIT(sizeof(buffer))
(gdb) list 
1613	{
1614	    char buffer[MAX_TERMINFO_LENGTH];
1615	
1616	    if (TcOutput())
1617		trim_trailing();
1618	    _nc_SPRINTF(buffer, _nc_SLIMIT(sizeof(buffer))
1619			"%s%s", infodump ? "use=" : "tc=", name);
1620	    wrap_concat1(buffer);
1621	}
1622	
(gdb) 


Actual results:

crash

Expected results:

crash

Additional info:


This vulnerability is detected by team OWL337, with our custom fuzzer collAFL. Please contact ganshuitao   and chaoz.cn if you need more info about the team, the tool or the vulnerability.