Buffer overflow in the Unescape function in common/util/hxurl.cpp and player/hxclientkit/src/CHXClientSink.cpp in Helix Player 1.0.6 and RealPlayer allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a URL argument containing a % (percent) character that is not followed by two hex digits.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.