Farrow was among the reporters who first broke news on the sexual-misconduct allegations against Harvey Weinstein previous year.
The directors' statement said that "all allegations of personal misconduct are to be taken seriously", and that the group would investigate any claims that violated the company's policies. Moonves resisted that deal because he believed CBS's prospects were better without taking on Viacom's turnaround challenges.
One of Hollywood's most powerful executives is facing allegations of misconduct in a soon-to-be-released article from The New Yorker. "While that litigation process continues, the CBS management team has the full support of the independent board members", the statement said.
This comes as Moonves is locked in a legal battle with Shari Redstone, a billionaire heiress and media executive who wants to remerge Viacom and CBS, since she owns a controlling share in both companies.
The New Yorker was awarded the Pulitzer Prize gold medal for public service for stories published previous year by Farrow, a contributing writer, that exposed the alleged pattern of sexual predation by movie producer Harvey Weinstein.
The New Yorker did not immediately respond to Reuters' request for comment.
Ms Redstone and Mr Moonves are now battling in the courts as he tries to thwart her plan to merge the two companies.
Moonves, who also serves as CBS Corporation's CEO and Chairman of the Board, becomes one of the biggest entertainment figures to be accused of sexual misconduct during the ongoing wave of stories and scandals that begat the current #MeToo movement. The statement added: "We will continue to focus on creating value for our shareowners". He was appointed chairman and CEO in 2003.