The signing of a new contract will be seen as a message to the squad that Lieberknecht's long-term future is secure, in spite of the threat of an immediate relegation back down to the second division.
"This is a clear signal in our current plight," said the club's chairman Sebastian Ebel. "We are convinced of the concept we have and those in charge should be allowed to carry on their work in peace and quiet.
"We still have a long way to go before reaching our goal."
Lieberknecht, who has been in charge of Braunschweig since 2008 and ended their 28-year wait for Bundesliga football, said he was "honoured" by the new deal.
"I was addicted to Braunschweig from day one," he said on the club's website. "I identify myself 1,000 per cent to this club and the city.
"We have some exciting challenges ahead because we want to stabilise Eintracht in professional football.
"I'm delighted with this show of faith."
Braunschweig go into Saturday's clash at the Eintracht Stadion with a deficit of four points to make up on safety, and with 12 games in which to do so.
Gladbach have an even greater deficit to make up on the top four having gone seven games without a win.
"I think after two straight draws, a win is now overdue," coach Lucien Favre said.
The Foals have slumped to sixth in the table and a further defeat could cost them their place in the top six and jeopardise their hopes of playing in Europe next season.
"I'm not concerned. Of course we want to win, but what's important for me is that we stop conceding unnecessary goals," he added.
Juan Arango is a doubt for Gladbach due to a groin strain.