---------------------------------------------------------------------- Bist Du interessiert an einem neuen Job in IT-Sicherheit? Secunia hat zwei freie Stellen als Junior und Senior Spezialist in IT- Sicherheit: http://secunia.com/secunia_vacancies/ ---------------------------------------------------------------------- TITLE: Juniper Netscreen IPSec VPN Username Enumeration Weakness SECUNIA ADVISORY ID: SA16474 VERIFY ADVISORY: http://secunia.com/advisories/16474/ CRITICAL: Not critical IMPACT: Exposure of system information WHERE: >From remote OPERATING SYSTEM: NetScreen ScreenOS 5.x http://secunia.com/product/2569/ NetScreen ScreenOS 4.x http://secunia.com/product/695/ NetScreen ScreenOS 3.x http://secunia.com/product/798/ NetScreen ScreenOS 2.x http://secunia.com/product/1395/ DESCRIPTION: NTA Monitor has reported a weakness in Juniper Netscreen VPN, which can be exploited by malicious people to gain knowledge of certain information. The weakness is caused due to the device returning different responses depending on whether or not a valid username is supplied. This can be exploited to enumerate valid usernames, which can be used to obtain password hashes. Successful exploitation requires that the device is configured to use IKE aggressive mode with pre-shared key authentication. The weakness has been reported in ScreenOS software versions up to 5.2.0. SOLUTION: Use certificate authentication instead of pre-shared key authentication. PROVIDED AND/OR DISCOVERED BY: NTA Monitor ORIGINAL ADVISORY: NTA Monitor: http://www.nta-monitor.com/news/vpn-flaws/juniper/netscreen/index.htm ---------------------------------------------------------------------- About: This Advisory was delivered by Secunia as a free service to help everybody keeping their systems up to date against the latest vulnerabilities. Subscribe: http://secunia.com/secunia_security_advisories/ Definitions: (Criticality, Where etc.) http://secunia.com/about_secunia_advisories/ Please Note: Secunia recommends that you verify all advisories you receive by clicking the link. Secunia NEVER sends attached files with advisories. Secunia does not advise people to install third party patches, only use those supplied by the vendor. ---------------------------------------------------------------------- Unsubscribe: Secunia Security Advisories http://secunia.com/sec_adv_unsubscribe/?email=packet%40packetstormsecurity.org ----------------------------------------------------------------------