Apple has released an iOS update to fix problems with Exchange for iPhones, but is yet to patch a critical security flaw that allows lockscreens to be bypassed.
The iOS 6.1.2 update "fixes an Exchange calendar bug that could result in increased network activity and reduced battery life", the firm said in a short statement.
However, there is no mention of a fix for the critical flaw that allows anyone to bypass the passcode screen and access information on iPhones.
The flaw was highlighted in a YouTube video posted on the 31January. Viewers were shown how to unlock iPhones using a using a series of steps involving the emergency call screen, power button and home button.
The process can be completed in less than a minute and allows users to access a phone's contacts, photos and call logs.
This isn't the first issue Apple has encountered with iOS 6.1, which was released at the end of January.
It was reported that many iPhone 4S users were unable to make calls, send text messages or browse the internet after upgrading to iOS 6.1. Vodafone even warned customers not to install iOS 6.1 until the bug was fixed, which resulted in iOS 6.1.1, being pushed out to iPhone 4S users.
Updated: Since news of the Exchange flaw being fixed was first published, the developers at jailbreak specialists Evad3rs have updated their toolkit to accommodate devices running iOS 6.1.2.
The group's new Evasi0n version 1.4 jailbreaking kit allows iPhone users to run unsigned code on theirs device, which lets them alter the look and feel of the iOS operating system and use applications that haven't been downloaded from the Apple App Store.
The group claim the jailbreak will work with devices running iOS 6 or later, but users are advised to backup their data using Apple's iCloud service before attempting to run it.
Updated: Further to the above, it has since been reported by IT Pro that Apple has already pushed out a beta version of its iOS 6.1.3 update that should prevent the Evasi0n jailbreak working, and fix the lock-screen hack issue.
David Wang, one of Evasion's creators, told Forbes he has analysed the iOS 6.1.3 beta update and discovered that it features patches for at least one of the five bugs the jailbreak exploits.
"If one of the vulnerabilities doesn't work, Evasion doesn't work," explained Wang.
"We could replace that part with a different vulnerability, but [Apple] will probably fix most, if not all, of the bugs we've used when 6.1.3 comes out."
