The System Logs implementation in Apple iOS before 6 does not restrict /var/log access by sandboxed apps, which allows remote attackers to obtain sensitive information via a crafted app that reads log files.
https://exchange.xforce.ibmcloud.com/vulnerabilities/78718
http://support.apple.com/kb/HT5503
http://lists.apple.com/archives/security-announce/2012/Sep/msg00003.html