2181
Shortly after the Struts 2 vulnerability was discovered and documented last week , researchers at Cisco 's Talos said they 'd observed it under “ active attack ” .
 ( discover vulnerability: was discovered,  last week: time, the Struts 2 vulnerability: vulnerability) 
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: was discovered,  last week: time, the Struts 2 vulnerability: vulnerability) 