Steam has recently released updates to Counter-Strike and Condition Zero. The updates will be applied automatically when your Steam client is restarted. The changes include:
Counter-Strike and Condition Zero
Prevent Russian Walking exploit
Server changes
Fixed players being kicked from servers with an INVALID_STEAM_TICKET rejection
Added a message to the server console to show when the server has reconnected to Steam
Made map name and other variables reported by the server stay more current
Fixed mp_timeleft not updating in server rules (or any unlogged cvar for that matter)
Show HLTV being connected in the player count for pings
Fixed HLTV staying in players list even after disconnect
Fixed server hang when a user connects with a specially crafted info string
Fixed occasional crash under Linux on startup for SMP machines (Linux)
Cleaned up hlds_run script (Linux)
There have also been reports of players crashing in game due to the update. Hopefully Valve will fix this soon.
Source: SteamPowered