Bug 1464684 - Null pointer dereference vulnerability in _nc_save_str function of ncurses tool with latest verison(6.0)
Summary: Null pointer dereference vulnerability in _nc_save_str function of ncurses to...
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: ncurses
Version: 7.5-Alt
Hardware: x86_64
OS: Linux
Target Milestone: rc
: ---
Assignee: Miroslav Lichvar
QA Contact: BaseOS QE - Apps
Depends On:
TreeView+ depends on / blocked
Reported: 2017-06-24 14:17 UTC by owl337
Modified: 2017-08-02 12:36 UTC (History)
2 users (show)

Clone Of:
Last Closed: 2017-08-02 12:36:38 UTC

Attachments (Terms of Use)
Triggered by "captoinfo POC1" (89 bytes, application/x-rar)
2017-06-24 14:17 UTC, owl337
no flags Details

Description owl337 2017-06-24 14:17:07 UTC
Created attachment 1291504 [details]
Triggered by  "captoinfo POC1"

Description of problem:

As ncurses/tinfo/comp_scan.c made lexical scanning,the nc_curr_token.tk_valstring(line:400) was initialized to Null by crafted input. It  led to  denial of service(crash) when the variable was transferred to _nc_save_str function as Null pointer. 

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

How reproducible:

captoinfo $POC

Steps to Reproduce:

$gdb captoinfo
(gdb) set args $POC
(gdb) r
(gdb) bt
 #0 strlen () at ../sysdeps/x86_64/strlen.S:106 
#1 0x0000000000446c1a in _nc_save_str (string=0x0) at ../ncurses/./tinfo/alloc_entry.c:99
 #2 0x0000000000437037 in _nc_parse_entry (entryp=0x7fffffffaf98, literal=0, silent=false) at ../ncurses/./tinfo/parse_entry.c:463 
#3 0x0000000000431183 in _nc_read_entry_source (fp=<optimized out>, buf=<optimized out>, literal=0, silent=false, hook=0x0) at ../ncurses/./tinfo/comp_parse.c:227
 #4 0x0000000000402c57 in main (argc=<optimized out>, argv=<optimized out>) at ../progs/tic.c:929

Actual results:


Expected results:


Additional info:

Comment 2 Thomas E. Dickey 2017-06-28 00:29:10 UTC
Severity medium (fix will appear in the weekly updates).

Comment 4 Miroslav Lichvar 2017-08-02 12:36:38 UTC
As this issue seems to have a very low impact, it's currently not planned to be fixed in RHEL 7.

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