Bugtraq mailing list archives
SonicWall IKE pre-shared key length bug and security concern
From: Steven Griffin <sgriffin () BAYSTARCAPITAL COM>
Date: Tue, 27 Mar 2001 20:34:20 -0000
I have recently found a bug in the latest firmware (6.0.0.0) of SonicWall's Tele2 and SOHO firewalls. Product details: http://www.sonicwall.com/products/tele/details.html http://www.sonicwall.com/products/soho/details.html Bug disovery: I was recently configuring the Tele2 and SOHO versions of these firewalls in a gateway to gateway VPN using IPSec with IKE pre-shared keys. The home office gateway was a Cisco PIX 520 running the PIX OS 5.2(4). The Tele2 and SOHO firewalls were recently upgraded to the 6.0.0.0 firmware. The IPSec configuration was ESP-3DES ESP-MD5- HMAC. During my configuration setup I noticed that I could not configure an IKE pre-shared key longer than 48 bytes. Doing so caused the the 2nd phase IKE negotiation to fail on the PIX. I contacted the vendor (SonicWall) and reported the problem. They have replicated the problem and confirmed that it is indeed a bug in their firmware. I asked them for permission to inform BugTraq and they responded that it was indeed alright to post this here provided that I inform you that I found the bug and that to say that they will provide a fix for this problem as soon as possible. Security concern: Obviously the limitation of using only a 48 byte key as opposed to using a full 128 byte key degrades the overall security of the firewall. Workarounds: Do not use pre-shared keys. Use certificates, your own or from a third party CA, instead. If you must use pre-shared keys: Use only static gateway addresses if possible. Use a different key for each gateway. Turn on Perfect Forwared Secrecy. Set your key expiration time to a shorter interval. Configuration information for duplication: note: IP Addresses have been removed. PIX 520 with OS 5.2(4) relavant config: access-list 119 permit ip xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx access-list nonat permit ip xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx sysopt connection permit-ipsec sysopt ipsec pl-compatible crypto ipsec transform-set SonicFirewall esp-3des esp-md5-hmac crypto map Sonic-map 19 ipsec-isakmp crypto map Sonic-map 19 match address 119 crypto map Sonic-map 19 set peer xxx.xxx.xxx.xxx crypto map Sonic-map 19 set transform-set SonicFirewall crypto map Sonic-map interface outside isakmp enable outside isakmp key <48-byte key here> address xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx isakmp identity address isakmp policy 19 authentication pre-share isakmp policy 19 encryption 3des isakmp policy 19 hash md5 isakmp policy 19 group 1 isakmp policy 19 lifetime 28800 SonicWall with firmware 6.0.0.0 Note: sonicwall config is web based so I will post field names. datatypes in square brackets "[ ]" and field values after a colon ":" IP addresses have also been removed. Summary Tab: Enable VPN checkbox: Checked Disable all VPN Windows Networking (NetBIOS) broadcast [checkbox]: UnChecked Enable Fragmented Packet Handling [checkbox]: Checked Configuration Tab: Security Association [drop-down listbox]: SonicToPIX IPSec Keying Mode [drop-down listbox]: IKE using pre-shared secret Name [textbox] SonicToPix Disable This SA [checkbox]:UnChecked IPSec Gateway Address [textbox]:xxx.xxx.xxx.xxx Require XAUTH/RADIUS(only allows VPN clients) [checkbox]:UnChecked Enable Windows Networking (NetBIOS) broadcast [checkbox]:Checked Enable Perfect Forward Secrecy [checkbox]:UnChecked SA Life time (secs) [textbox]:28800 Encryption Method [drop-down listbox]:Strong Encrypt and Authenticate (ESP 3DES HMAC MD5) Shared Secret [textbox]:<48-byte key here> Destination Networks: [sub window]: IP Address [textbox]:xxx.xxx.xxx.xxx SubnetMask [textbox]:xxx.xxx.xxx.xxx Disclaimer and closing: I must say that I am not a security expert and I do not claim to be one. My opinions are my own. Use my opinions and the information in this posting at your own risk. My intention for posting this information is to inform the BugTraq community about a possible security concern. Steven Griffin sgriffin () baystarcapital com
Current thread:
- SonicWall IKE pre-shared key length bug and security concern Steven Griffin (Mar 27)
- <Possible follow-ups>
- Re: SonicWall IKE pre-shared key length bug and security concern Ben Nagy (Mar 28)