Reworked Unholy Might Wither duration

Is it a wording oversight, or is the Wither stack applied by the new Unholy Might permanent?

"

The Unholy Might buff no longer grants 30% of Physical Damage as extra Chaos Damage. It instead now provides 100% of Physical Damage Converted to Chaos Damage, and 25% chance to Apply Wither on Hit.

In every source for Wither that I'm aware of, it always specifies a duration - usually 2 seconds - e.g. in Nature's Reprisal "25% chance to inflict Withered for 2 seconds on hit."