updated 02:30 am EDT, Fri August 30, 2013
String of Arabic characters flaw mostly harmless, but annoying
A string of certain Arabic characters sent to devices running OS X 10.8.x and iOS 6.x can crash applications and make the Messages app unusable and cause both Safari and Chrome to crash. The problem has been fixed in beta releases of iOS 7 and OS X 10.9 Mavericks, but at present there is no official patch for the problem in the current releases of OS X and iOS. An unofficial fix has been made available for jailbroken devices.
Because the string of characters causes both the recipient's and sender's machines to experience the issues -- which include the aforementioned freezes and crashes as well as not allowing scanning of SSIDs for wireless networks -- the chances of being on the receiving end of the attack are very low. However, some have claimed that Apple has known about the flaw for six months already and has yet to protect the current or previous systems, 9to5Mac reports.
Hacker Filippo Bigarella has released a solution for the flaw for iOS's Mobile Safari on jailbroken devices, as well as a "dumb" patch for Webkit upon which all other iOS browsers rely. He says it is "not a definite solution, but it'll do" until Apple releases an update that fixes the issue.
The flaw doesn't allow malicious attacks or remote access, but just causes application freezes and crashes. The jailbreak fix allows apps normally affected by the problem to continue working.