Jailbreak iPhone iOS 4.2.1

By , Feb 7, 2011

iOS 4.2.1 has been released for a while now, and up until this weekend, there wasn’t a good and practical jailbreak for it. Sure RedSn0w did the trick but since it was a tethered jailbreak, it wasn’t very convenient.

Then came RedSn0w untethered jailbreak, which was better than its predecessor, but still wasn’t satisfying to most of us. Finally the Chronic Dev Team updated GreenPois0n, which brings a safe and reliable untethered jailbreak for iPhone iOS 4.2.1

How to Jailbreak iOS 4.2.1?

Should there be a new method to jailbreak iPhone 4.2.1, we will post it here and in our jailbreak section, but for the time being, GreenPois0n is your best bet.

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  • http://www.ndsr.net Lukong

    What if there isn’t a Spirit Jailbreak, what if this is Apple talking to us so we can screw up our idevices so that we would have to by another one.

    • Marrece

      I have a prob. I used greenpoison to jailbreak iPhone 4. Everything was working fine. The next day I had no sources and no sections. I try to add sources manually but they fail everytime. Can someone answer this for me thanks.

    • Jenni

      I want to unlock 3G 8gig on 4.2.1 what Is best method I don’t even know what a baseboard is? Pls be simple x

    • the HAM

      your on crack

      • LOL

        YOU’RE*

  • sara

    hi guys i make Jailbreak for 3gs Green poison 4.2.1

    and i have problem after jailbreak my camera and photos library not working I make restart again for jailbreak and still the same problem is there in solution

    • http://www.youtube.com aaa

      too bad

    • Paul Rushing

      Leave phone unplugged go to control panel, system, device manager look at devive manager now plug in phone if any changes are made in device manager click on it and the camera and etc should work.

  • mtsato

    Anyone know something about when unlock process will be released for Iphone 4 ? I’m stucked in IOS 4.1 baseband 02.10.4.

  • KraftWiz

    UNLOCK

    For all you guys looking for an unlock for 4.2.1 with baseband 05.15.04., why not upgrade to 06.15. and unlock with ultrasnow ??

    Why is that such a big problem?

    If there is an unlock already available, why should the dev team work on another one ??

    • zero cool

      Because not all of us are comfortable changing to a baseband that will require a custom firmware should you ever need to restore the devise.that’s a huge draw back.not only is it obvious you voided the warranty on the device but you can never restore it to a factory condition again.a simple jailbreak can be reversed and with little effort all traces of illicit activity removed there by making it fairly innocuous.changing the BB to that of the iPad while functional is currently irreversible and could have yet unknown consequences further down the road.

  • Kit

    can anyone help me please, after jailbreaking my i phone 4 through green poison, every time i make a call it hangs or when i end a call it hangs and it says that springboard crashed, restart program. help me please i don’t want to encounter this problem every time i make a call thank you

    • joshh

      Well best thing to do would be to restore it all on itunes :) but obv all your cydiaa will go :L

  • ELena

    For some reason everything goes black when i try to jailbreak iphone and it doesn’t work at the end,
    I don’t really know what I don’t do right, can u please help me to solve the problem?
    Thanks

    • monkers

      What model? what version?

      • ELena

        3 G, 4.2.1.
        It was really frustrating coz nothing was working…it was just black screen, so the only possibility for me was to restore the latest version and back up.
        What do u think went wrong?

      • Monkers

        Not sure the 3G is supported mate

      • http://www.youtube.com aaa

        dun tell u

      • Yasine abdoollah

        I want to unlock my I phone 4 . 4.3 4.2.1

  • Diego

    hi there you can jildbreak your iphone 3G with redsnow only just download the Firmware on/
    http://www.felixbruns.de/iPod/firmware/ and then just let it run and should be alright mate.
    i have done it already and it works perfectly

  • Diego

    what i need to know did anyone knows how to unlock iphone 4?? i’ve just jailbreak my iphone4 with greenpoison but not unlocked.. all other iphone 3gs wokd ok but not on iphone 4..
    if you know please provide some of the information of how to do it.

    kind regards
    Diego

  • monkers

    No BB unlock on 03.10.01 till 4.3 is announced mister.

  • http://www.youtube.com aaa

    who is my mom??

  • Bear

    I have an I phone 3g I already have cydia but I don’t have the latest version .

  • Steeve

    Pleaaaaaase i need help :( i have 3gs 3.1.2 running on baseband 05.11.07 was made in the 48th week, and since i bought it 1 year ago i have tried every possible way to unlock it but with no benefit, its jailbroken, and everytime it turns off i have to run blackrain again and again :( , if i upgraded to iOS 4.2.1 will Greenp0ison solve my issue and it will be unlocked?? and do i have to upgrade to baseband 06.15.00, and how to do so?? pleeeeeeeease somebody professional answer me i need serious help

  • Dave

    my battery discharge twice as fast when is jailbroken i restored the battery is fine i rejailbroked and the battery is discharging very quick anyone with the same problem ??

  • Dave

    is jailbroken with green p o is o n rc6 thanks !!!

  • http://www.ps3repairs.com.au John

    great finally a decent jailbreak for 4.2.1

  • G

    “great finally a decent jailbreak for 4.2.1″
    Which one are you refering to???

  • Koleen Javellana

    HELP!!

    I have an Iphone 3G iOS 4.2.1
    Jailbroke my phone and everything is fine.
    I check my Cydia and there are no sources. When I manually add sources nothing happens. Help! :(

  • Koleen Javellana

    HELP!!

    I have an Iphone 3G iOS 4.2.1
    Jailbroke my phone and everything is fine.
    I check my Cydia and there are no sources. When I manually add sources nothing
    happens. Help! :(

  • Dave1980

    Have had many issues with tethered jailbreak and unlock on 4.3.2, GEVEY SimCard useless, however, managed to get hands on i4 that is running 4.2.1 and did jailbreak no problem with greenpois0n, but now only problem is photo library and factory camera app does not function! Constant “rebuilding library” msg appears or it simply goes back to home screen… Extremely frustrating, wondering if there is any remedy that is reliable available?, please no device management through computer bullshit, or iPhone browser non-sense..these have not rectified the problem…. Please anyone with advice or reliable method to fix this would be unbelievably appreciated…

  • Adie

    I unlocked my Iphone 3GS simply, with no problems some months ago, I have an Iphone 3G (for my son) with 4.2.1 and tried pretty much all of the jailbreak progs out there and I just cant get it done. It was unlocked once it was out of contract I believe, which shouldnt make any difference??
    all the programs keep requesting me to retry . Does anyone have any tips?

  • Mo

    Hello guys,

    I have a problem with my iPhone 3G, unexpectly I removed Cydra from my iPhone and I don’t know to return it back again!!!! please give me advise if anyone knows.

    thanks in advance :)

  • sallu

    hey guys,
    can someone tel me a solution to my problem.i was costumizing my iphone 3gs and wen it finished found out that the cydia icon is missing.the cydia icon jst disappeared…plx let me kno guys if dere is a solution of my problem
    thanks

  • Jailbreak

    nono not work :(

    • Sayhar

      haha after reading this im def not getting this greenpoision :X

  • Rudedog

    Hey help needed
    I Jailbroke my iPhone using green poison. My content on my web pages and some videos on some apps I have won’t work. I need helping fixing this problem. All it shows is a play sign with a line trough it. Please help if anyone can thanks!