The report, submitted to the UN Human Rights Council by the UN independent expert on privacy, Joe Cannataci, said traditional privacy safeguards such as rules on phone tapping were outdated in the digital age, Reuters reported.
"It's time to start reclaiming cyberspace from the menace of over-surveillance," Cannataci told the Council.
With government's worldwide demanding data from firms such as Microsoft, Google, Facebook, Apple and Twitter, it did not make sense to rely entirely on US legal safeguards, and creating an "international warrant" for data access or surveillance would unify global standards, he said.
"What the world needs is not more state-sponsored shenanigans on the Internet but rational, civilized agreement about appropriate state behavior in cyberspace," the report said. "This is not utopia. This is cold, stark reality."
Cannataci was appointed as the first "Special Rapporteur on the right to privacy" in 2015, following the uproar caused by revelations by Edward Snowden, a former US security contractor who once worked at the US mission in Geneva.
His report was submitted last week, before the latest publication by anti-secrecy group WikiLeaks of what it said were thousands of pages of internal CIA discussions of hacking techniques of smartphones and other gadgets.
The United States did not react to Cannataci's report, but many countries welcomed it and agreed that online privacy standards should be as strong as offline standards.
China's diplomat at the Council said rapid technological advances and the "drastic increase worldwide in the violation of privacy" made it urgent to enhance protection, while Russia's representative said Cannataci's report was "extremely topical".
Venezuela, Iran and Cuba all welcomed Cannataci's work and criticized international surveillance.
A draft legal text was being debated by activists and "some of the larger international corporations" and was expected to be published within a year, Cannataci said.
In his report, he criticized populist laws that intruded on privacy in the name of fighting terrorism.
He said such sweeping but unproven powers were based on fear alone, and compared them to US President Donald Trump's order restricting travel from six Muslim-majority countries: Iran, Libya, Syria, Somalia, Sudan and Yemen.
"The level of the fear prevents the electorate from objectively assessing the effectiveness of the privacy-intrusive measures proposed," he wrote.
"Trying to appear tough on security by legitimizing largely useless, hugely expensive and totally disproportionate measures which are intrusive on so many people’s privacy – and other rights - are patently not the way governments should go."