icu - security update

A vulnerability has been found in the International Components
for Unicode (ICU) library:

• CVE-2015-4760
  It was discovered that ICU Layout Engine was missing multiple
  boundary checks. These could lead to buffer overflows and memory
  corruption. A specially crafted file could cause an application
  using ICU to parse untrusted font files to crash and, possibly,
  execute arbitrary code.

For the squeeze distribution, these issues have been fixed in version
4.4.1-8+squeeze4 of icu.

We recommend to upgrade your icu packages.