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U iptables-u, liste pravila poznate kao lančevi se obrađuju sekvenčno. Među njima, tri osnovna lanca su univerzalno prisutna, sa dodatnim kao što je NAT koji može biti podržan u zavisnosti od mogućnosti sistema.
Input lanac: Koristi se za upravljanje ponašanjem dolaznih veza.
Forward lanac: Koristi se za upravljanje dolaznim vezama koje nisu namenjene lokalnom sistemu. Ovo je tipično za uređaje koji deluju kao ruteri, gde primljeni podaci treba da budu prosleđeni drugoj destinaciji. Ovaj lanac je relevantan pre svega kada sistem učestvuje u rutiranju, NAT-ovanju ili sličnim aktivnostima.
Output lanac: Posvećen regulisanju odlaznih veza.
Ovi lanci omogućavaju uređeno procesiranje mrežnog saobraćaja, omogućavajući specificiranje detaljnih pravila koja regulišu protok podataka u, kroz i iz sistema.
# Delete all rulesiptables-F# List all rulesiptables-Liptables-S# Block IP addresses & portsiptables-IINPUT-sip1,ip2,ip3-jDROPiptables-IINPUT-ptcp--dport443-jDROPiptables-IINPUT-sip1,ip2-ptcp--dport443-jDROP# String based drop## Strings are case sensitive (pretty easy to bypass if you want to check an SQLi for example)iptables-IINPUT-ptcp--dport<port_listening>-mstring--algobm--string'<payload>'-jDROPiptables-IOUTPUT-ptcp--sport<port_listening>-mstring--algobm--string'CTF{'-jDROP## You can also check for the hex, base64 and double base64 of the expected CTF flag chars# Drop every input port except someiptables-PINPUTDROP# Default to dropiptables-IINPUT-ptcp--dport8000-jACCEPTiptables-IINPUT-ptcp--dport443-jACCEPT# Persist Iptables## Debian/Ubuntu:apt-getinstalliptables-persistentiptables-save>/etc/iptables/rules.v4ip6tables-save>/etc/iptables/rules.v6iptables-restore</etc/iptables/rules.v4##RHEL/CentOS:iptables-save>/etc/sysconfig/iptablesip6tables-save>/etc/sysconfig/ip6tablesiptables-restore</etc/sysconfig/iptables
Suricata
Instalacija & Konfiguracija
# Instalacija Suricatesudoapt-getinstallsuricata# Konfiguracija Suricatesudonano/etc/suricata/suricata.yaml# Podešavanje interfejsa za nadgledanjesudonano/etc/suricata/suricata.yaml# Podešavanje pravila za detekcijusudonano/etc/suricata/suricata.yaml# Pokretanje Suricatesudosuricata-c/etc/suricata/suricata.yaml-ieth0
# Install details from: https://suricata.readthedocs.io/en/suricata-6.0.0/install.html#install-binary-packages# Ubuntuadd-apt-repositoryppa:oisf/suricata-stableapt-getupdateapt-getinstallsuricata# Debianecho"deb http://http.debian.net/debian buster-backports main"> \/etc/apt/sources.list.d/backports.listapt-getupdateapt-getinstallsuricata-tbuster-backports# CentOSyuminstallepel-releaseyuminstallsuricata# Get rulessuricata-updatesuricata-updatelist-sources#List sources of the rulessuricata-updateenable-sourceet/open#Add et/open rulesetssuricata-update## To use the dowloaded rules update the following line in /etc/suricata/suricata.yamldefault-rule-path:/var/lib/suricata/rulesrule-files:-suricata.rules# Run## Add rules in /etc/suricata/rules/suricata.rulessystemctlsuricatastartsuricata-c/etc/suricata/suricata.yaml-ieth0# Reload rulessuricatasc-cruleset-reload-nonblocking## or set the follogin in /etc/suricata/suricata.yamldetect-engine:-rule-reload:true# Validate suricata configsuricata-T-c/etc/suricata/suricata.yaml-v# Configure suricata as IPs## Config drop to generate alerts## Search for the following lines in /etc/suricata/suricata.yaml and remove comments:-drop:alerts:yesflows:all## Forward all packages to the queue where suricata can act as IPSiptables-IINPUT-jNFQUEUEiptables-IOUTPUT-jNFQUEUE## Start suricata in IPS modesuricata-c/etc/suricata/suricata.yaml-q0### or modify the service config file as:systemctleditsuricata.service[Service]ExecStart=ExecStart=/usr/bin/suricata-c/etc/suricata/suricata.yaml--pidfile/run/suricata.pid-q0-vvvType=simplesystemctldaemon-reload
Postoji stotine opcija dostupnih u Suricati za pretragu specifičnog paketa koji tražite, ovde će biti navedeno ako se pronađe nešto interesantno. Proverite dokumentaciju za više informacija!
# Meta Keywordsmsg:"description"; #Set a description to the rulesid:123#Set a unique ID to the rulerev:1#Rule revision numberconfigclassification:not-suspicious,NotSuspiciousTraffic,3#Classifyreference:url,www.info.com#Referencepriority:1; #Set a prioritymetadata:keyvalue,keyvalue; #Extra metadata# Filter by geolocationgeoip:src,RU;# ICMP type & Codeitype:<10;icode:0# Filter by stringcontent:"something"content:|616161|#Hex: AAAcontent:"http|3A|//"#Mix string and hexcontent:"abc"; nocase; #Case insensitiverejecttcpanyany ->anyany (msg: "php-rce"; content:"eval"; nocase; metadata:tagphp-rce; sid:101; rev:1;)# Replaces string## Content and replace string must have the same lengthcontent:"abc"; replace:"def"alerttcpanyany ->anyany (msg: "flag replace"; content:"CTF{a6st"; replace:"CTF{u798"; nocase; sid:100; rev:1;)## The replace works in both input and output packets## But it only modifies the first match# Filter by regexpcre:"/<regex>/opts"pcre:"/NICK .*USA.*[0-9]{3,}/i"droptcpanyany ->anyany (msg:"regex"; pcre:"/CTF\{[\w]{3}/i"; sid:10001;)# Other examples## Drop by portdroptcpanyany ->any8000 (msg:"8000 port"; sid:1000;)
Da li radite u cybersecurity kompaniji? Želite li da vidite vašu kompaniju reklamiranu na HackTricks-u? Ili želite da imate pristup najnovijoj verziji PEASS-a ili preuzmete HackTricks u PDF formatu? Proverite SUBSCRIPTION PLANS!