To cut both ways

to have effects both advantageous and disadvantageous.

See also: Cut

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
His silence appears to me to cut both ways. There are several singular points about the case.
Barry Kent: "Our kids are never late into school but this has to cut both ways. The number of times we stand there waiting for them at the end of their day is unreal.
Successful relationships always have to have an element of sacrifice, but it has to cut both ways.