Re: [SR-Users] Bash Code Injection and 'exec' module

sorry, I attached wrong patch in previous post here is new with fixed body length comparison. On Thu, Sep 25, 2014 at 4:40 PM, Seudin Kasumovic &lt;seudin.kasumovic(a)gmail.com <mailto:seudin.kasumovic@gmail.com>> wrote: Hi kamailio users, we are witnesses of new discovered bug in bash: Bash Code Injection Vulnerability via Specially Crafted Environment Variables (CVE-2014-6271) https://access.redhat.com/node/1200223 As exec module exports all SIP headers in environment so it's was easy to push bash command. There is attached simple kamailio test config file. With sipp we sent header to output 123 into file /tmp/123 like this: User-Agent: () { :;}; echo 123 > /tmp/123 Debug output from kamailio is: 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_CONTENT_LENGTH=135 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_CONTENT_TYPE=application/sdp 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_ALLOW=INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH * 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_USER_AGENT=() { :;}; echo 123 > /tmp/123* 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_SUBJECT=Performance Test 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_MAX_FORWARDS=70 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_CONTACT=<sip:T00157@198.51.100.2:5060 <http://sip:T00157@198.51.100.2:5060>> 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_CSEQ=1 INVITE 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_CALLID=1-5394(a)198.51.100.2 <mailto:1-5394@198.51.100.2> 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_TO=+442033998806 <tel:%2B442033998806> <sip:+442033998806 <tel:%2B442033998806>@orange.voip> 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_FROM=+442033998833 <tel:%2B442033998833> <sip:T00157@orange.voip>;tag=5394SIPpTag001 5(30147) DEBUG: exec [exec_hf.c:278]: print_hf_var(): SIP_HF_VIA=SIP/2.0/UDP 198.51.100.2:5060;branch=z9hG4bK-5394-1-0 5(30147) DEBUG: exec [exec_mod.c:175]: w_exec_msg(): executing [/bin/true] ls /tmp shows new created file !!! I created simple patch to fix this issue in exec module based on suggestion from RedHat until you fix your bash what is recommended. -- Seudin Kasumovic -- MSC Seudin Kasumovic Tuzla, Bosnia _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users(a)lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users