-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Title: Juniper Networks NetScreen Advisory 59147 Date: 3 August 2004 Version: 1 Impact: Remote crash of ScreenOS via the SSHv1 service Affected Products: Juniper Networks NetScreen firewalls with SSHv1 enabled Unaffected Products: Juniper Networks NetScreen firewalls with SSH disabled or SSHv2 enabled Max Risk: High Summary: The Juniper Networks NetScreen firewall SSHv1 service implementation has a bug which allows an attacker to crash ScreenOS. Details: A malicious person who can connect to the SSHv1 service on a Juniper Networks Netscreen firewall can crash the device before having to authenticate. Upon execution of the attack, the firewall will reboot or hang, which will prevent traffic to flow through the device. Recommended Actions: Customers have a number of choices to mitigate the attack: Option 1: Upgrade the firewall to one of the following versions of ScreenOS: Version Availability 5.0.0r8 Now 5.0.0r8.1 Now 4.0.0r13 Now 4.0.1r11 Now 4.0.3r8 Now 4.0.1-Dial2r5 Now 4.0.1-SBRr5 Now 4.0.1-IGMP3r4 Now 4.0.1-MCASTr2 Now 3.0.3r9 Now Option 2: Disable SSHv1 and manage the device through other means (such as HTTPS). Option 3: Configure the firewall to only accept connections from trusted IP addresses. Additionally, enabling IP Spoof protection will add an additional layer of security. Patch Availability: Juniper Networks currently has updated versions of ScreenOS available for immediate download. How to get ScreenOS: Customers with a valid product warranty or a support contract may download the software from the Juniper Networks CSC web portal: http://www.juniper.net/support/ For all other customers, including those with expired support contracts, please call your regional Juniper Networks TAC (JTAC) center. To get a listing of JTAC phone numbers, please sign up for a CSC account at: http://www.juniper.net/entitlement/setupAccountInfo.do Select option 2 from the telephone menu and be sure to select the correct product from the phone tree. Once connected with an engineer state that you are calling in regards to a Security Advisory and provide the title of this notice as evidence of your entitlement to the specified release. Please note that customers with expired support contracts will be provided only with the software update for the version of software that they are currently using, when that version becomes available. As with any new software installation, Juniper Networks customers planning to upgrade to any version of ScreenOS should carefully read the release notes and other relevant documentation before beginning any upgrade. Juniper Networks would like to thank Mark Ellzey Thomas of NaviSite for discovering this issue and working with us. If you wish to verify the validity of this Security Advisory, the public PGP key can be accessed at: http://www.juniper.net/support/security/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Juniper NetScreen Security Response Team iD8DBQFBD/UuW2Bw6QjqXRcRAlbgAJ0aIrji2u80xRJvPXhYpakdpCNZTwCdEZgs VF13cW6F3qfOE7hwdsDw6Lo= =Ebjo -----END PGP SIGNATURE-----