iSSLFix is a tweak by jan0 that closes the SSL vulnerability found in firmwares below iOS 4.3.5.
Apple closed this vulnerability in its latest release; however, those who used JailbreakMe to jailbreak or those who are jailbroken on iOS 4.3.4 or lower are still in danger.
Fix for iOS SSL vulnerability CVE-2011-0228 for iOS
Rebooting your device will be required after installing this fix
You can download iSSLFix from the BigBoss Cydia Repository.
dpkg -i isslfix.deb launchctl unload /System/Library/LaunchDaemons/com.apple.securityd.plist
launchctl load /System/Library/LaunchDaemons/com.apple.securityd.plist
Visit https://issl.recurity.com to check if this is working.
Because securityd is restarted, existing processes and daemons will lose their “connexion” to it and most calls to the Security framework (Keychain, cert validation, etc) will fail : iTunes wont be able to connect to the device, apps will be unable to access the keychain, etc. These issues should disappear after a device reboot.
If securityd crashed (check /Library/Logs/CrashReporter/), remove the package (dpkg -r isslfix) before rebooting.