[Full-Disclosure] Re: Check Point FW-1: attack against syslog daemon possible

From: Dr. Peter Bieringer (pbieringerat_private)
Date: Thu Mar 27 2003 - 02:59:49 PST

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    Hi again,
    
    now we are finished the investigation of FW-1 4.1 (SP6) with following 
    result:
    
    In our lab the syslog daemon of Check Point FW-1 4.1 didn't crash in case 
    of sending "/dev/urandom" via "nc", but this floods the log without any 
    rate limiting.
    
    Also the syslog messages were not filtered.
    
    Note also that that improving the ruleset didn't help in cases where 
    trusted and untrusted nodes are sharing the same network, because in UDP 
    packets the sender IP address can be spoofed (successfully tested with 
    "sendip" against FW-1 4.1).
    
    To avoid spoofing, only MAC based ACLs on gateways (if available) will help 
    or establishing a dedicated (V)LAN for trusted sources only.
    
    
    We've updated our advisory once again:
    
    http://www.aerasec.de/security/advisories/txt/
     checkpoint-fw1-ng-fp3-syslog-crash.txt
    http://www.aerasec.de/security/advisories/
     checkpoint-fw1-ng-fp3-syslog-crash.html
    
    
    Hope this helps,
    	Peter
    -- 
    Dr. Peter Bieringer                             Phone: +49-8102-895190
    AERAsec Network Services and Security GmbH        Fax: +49-8102-895199
    Wagenberger Straße 1                           Mobile: +49-174-9015046
    D-85662 Hohenbrunn                       E-Mail: pbieringerat_private
    Germany                                Internet: http://www.aerasec.de
    
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