The MITRE CVE dictionary describes this issue as:
Multiple integer overflows in the strfmon implementation in the GNU C Library (aka glibc or libc6) 2.10.1 and earlier allow context-dependent attackers to cause a denial of service (memory consumption or application crash) via a crafted format string, as demonstrated by a crafted first argument to the money_format function in PHP, a related issue to CVE-2008-1391.
Find out more about CVE-2009-4880 from the
MITRE CVE dictionary dictionary and
Red Hat does not consider this bug to be a security issue. Properly written application should not use arbitrary untrusted data as part of the format string passed to functions as strfmon or printf family functions.