A hostapd security update has been released for Debian 6 LTS

Package : hostapd
Version : 1:0.6.10-2+squeeze2
CVE ID : CVE-2015-4142

A vulnerability was found in WMM Action frame processing in a case where
hostapd is used to implement AP mode MLME/SME functionality (i.e., Host AP
driver of a mac80211-based driver on Linux).

This vulnerability can be used to perform denial of service attacks by
an attacker that is within radio range of the AP that uses hostapd for
MLME/SME operations.

For Debian 6 “Squeeze”, this vulnerability has been fixed in version
1:0.6.10-2+squeeze2 of hostapd. We recommend that you upgrade your
hostapd package.

  Hostapd security update for Debian 6 LTS