Security Update 2018-004 (Sierra and El Capitan)
Apple has released Security Update 2018-004 for macOS 10.12 Sierra and 10.11 El Capitan, patching security vulnerabilities that the company addressed in 10.13.6 High Sierra (see “Apple Releases macOS 10.13.6, iOS 11.4.1, tvOS 11.4.1, and watchOS 4.3.2,” 9 July 2018). The security updates for both Sierra and El Capitan address a memory corruption issue that would enable a malicious application to break out of its sandbox, patch a data leakage vulnerability related to the Lazy FP state restore issue with Intel Core-based microprocessors (see this Secplicity article for more information), and resolve another memory corruption issue that could allow an application to gain elevated privileges. (Free. For macOS 10.12.6 Sierra, 750 MB; for macOS 10.11.6 El Capitan, 859 MB; release notes)
I know this is an older thread, and I admit I haven’t used my MacBook Pro for sometime (an older 2009 model running El Capitan). But when I did this week, I saw a security update needed to be done, SU 2018-004. I did this update, it gave me a message, update didn’t work, try again. So I did, (thinking it was just a connectivity issue?) the update took, restarted the MacBook. Now during start up, it freezes or gets in to some kind of loop and can’t get past the start up screen? Googled what to do, tried restarting in safe mode, used disk utility and the first aid option to correct one or two hd issues it found. Redid the DU FA a second time and it showed everything was ok. Did a restart from the apple menu, still freezes up in start up. Anyone else have this issue?
I think this might be the same annoying bug several of us came across with a HS sec update not so long ago.
Reboot holding shift (safe boot). That should allow the boot to complete. Launch App Store. The sec update should still show. Install it again. Then you should be able to reboot properly. If not, rinse wash repeat.
Thanx Simon, I did get to the safe mode, but there was no later SU to apply? I took the computer to a specialist and he said he thinks the hard drive failed. But it was completely fine, and only 50% filled prior to the update. Do you think the fix would be SU 2018-005?
While still in Safe Mode, apply all the updates being offered. Repeat until no more updates are shown (cmd-r to refresh list).
Try downloading the update directly from the Apple.com download page (not the App Store) and reinstalling it by hand. See https://support.apple.com/downloads and search for the update there.