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The Signalling System No. 7 ( SS7 ) telephony signaling protocol used to establish interoperability across some 800 + service providers worldwide , is deeply vulnerable to interception by hackers , criminals , and corrupt insiders .
 ( discover vulnerability: vulnerable,  service providers: vulnerable system owner, The Signalling System No. 7: vulnerable system, SS7: vulnerable system, interception by hackers , criminals , and corrupt insiders: capabilities) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: phishing, data breach, ransom, discover vulnerability, patch vulnerability, Arguments type: vulnerable system, capabilities, vulnerability, number of victim, issues addressed, compromised data, damage amount, common vulnerabilities and exposures, victim, patch number, number of data, tool, discoverer, time, purpose, place, payment method, releaser, vulnerable system version, attacker, supported platform, patch, price, vulnerable system owner, trusted entity, attack pattern. 
Text: {0} 
Answer:
 ( discover vulnerability: vulnerable,  service providers: vulnerable system owner, The Signalling System No. 7: vulnerable system, SS7: vulnerable system, interception by hackers , criminals , and corrupt insiders: capabilities) 