The MITRE CVE dictionary describes this issue as:
Multiple buffer overflows in net/wireless/nl80211.c in the Linux kernel before 126.96.36.199 allow local users to gain privileges by leveraging the CAP_NET_ADMIN capability during scan operations with a long SSID value.
Find out more about CVE-2011-2517 from the
MITRE CVE dictionary dictionary and
This issue did not affect the versions of Linux kernel as shipped with Red Hat
Enterprise Linux 4 as it did not provide support for the Linux wireless LAN (802.11) configuration API. This has been addressed in Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG via https://rhn.redhat.com/errata/RHSA-2011-1212.html, https://rhn.redhat.com/errata/RHSA-2011-1189.html, and https://rhn.redhat.com/errata/RHSA-2011-1253.html.