SAN FRANCISCO — U.S. agencies on Tuesday offered new details about how Chinese state-sponsored hackers have used publicly known vulnerabilities to target internet service providers and major telecommunications firms around the globe over the last two years. Taking advantage of common vulnerabilities and exposures (CVEs) allows malicious actors backed by Beijing to break into victim accounts and network infrastructure — via a virtual private network or another public-facing application — “without using their own distinctive or identifying malware,” the FBI, the National Security Agency and the Cybersecurity and Infrastructure Security Agency said in an advisory. The joint document is the…