This bug has been driving me insane lately - or if it is not the same bug then the symptoms are identical.

What I have is a 14.04.2 LTS server that has had a Rails app running for some time without this problem. Now, approx a month ago, I started seeing this problem where on Firefox I intermittently get the 'sec_error_bad_signature' error. I have not tried to reproduce it in Chrom(e/ium) since as said it happens only sometimes. When it happens on Firefox, a few reloads solve the problem.

BUT it's not only Firefox. I have a monitoring system by my host which gives me downtime on an HTTPS check approx 20 times a day, typically in two batches - probably because at some point Apache restarts and the error goes away for a while. The error it gets from the check is:

> Exception: #<OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv3 read server key exchange B: bad signature>

Also, I monitor sites with Uptimerobot too, which also gives a failure at same time. During a few hours it gives 10-20 up/down notifications as the web site is flaky.

In the Apache error log, I can see this:

> [Sun May 10 06:25:20.149372 2015] [ssl:warn] [pid 32429:tid 140264803096448] AH02292: Init: Name-based SSL virtual hosts only work for clients with TLS server name indication support (RFC 4366)
> [Sun May 10 06:25:20.149467 2015] [mpm_event:notice] [pid 32429:tid 140264803096448] AH00489: Apache/2.4.7 (Ubuntu) OpenSSL/1.0.1f mod_wsgi/3.4 Python/2.7.6 configured -- resuming normal operations
> [Sun May 10 06:25:20.149478 2015] [core:notice] [pid 32429:tid 140264803096448] AH00094: Command line: '/usr/sbin/apache2'
> [Sun May 10 07:29:00.154618 2015] [core:notice] [pid 32429:tid 140264803096448] AH00051: child pid 19109 exit signal Segmentation fault (11), possible coredump in /etc/apache2
*** Error in `/usr/sbin/apache2': double free or corruption (!prev): 0x00007f91b80096c0 ***
> [Sun May 10 07:42:06.978787 2015] [core:notice] [pid 32429:tid 140264803096448] AH00051: child pid 20347 exit signal Aborted (6), possible coredump in /etc/apache2
> [Sun May 10 14:53:43.497375 2015] [mpm_event:notice] [pid 32429:tid 140264803096448] AH00491: caught SIGTERM, shutting down
> [Sun May 10 14:53:44.534805 2015] [mpm_event:notice] [pid 28764:tid 140143992375168] AH00489: Apache/2.4.7 (Ubuntu) OpenSSL/1.0.1f mod_wsgi/3.4 Python/2.7.6 configured -- resuming normal operations
> [Sun May 10 14:53:44.534899 2015] [core:notice] [pid 28764:tid 140143992375168] AH00094: Command line: '/usr/sbin/apache2'
> [Sun May 10 15:39:34.413988 2015] [core:notice] [pid 28764:tid 140143992375168] AH00051: child pid 28768 exit signal Segmentation fault (11), possible coredump in /etc/apache2
*** Error in `/usr/sbin/apache2': double free or corruption (!prev): 0x00007f75b0006f80 ***
> [Sun May 10 16:31:14.678905 2015] [core:notice] [pid 28764:tid 140143992375168] AH00051: child pid 30167 exit signal Aborted (6), possible coredump in /etc/apache2
*** Error in `/usr/sbin/apache2': double free or corruption (!prev): 0x00007f75ac009780 ***
> [Sun May 10 19:46:56.937817 2015] [core:notice] [pid 28764:tid 140143992375168] AH00051: child pid 32308 exit signal Aborted (6), possible coredump in /etc/apache2
*** Error in `/usr/sbin/apache2': double free or corruption (!prev): 0x00007f75b0006f80 ***
> [Sun May 10 20:31:54.754358 2015] [core:notice] [pid 28764:tid 140143992375168] AH00051: child pid 6829 exit signal Aborted (6), possible coredump in /etc/apache2

Initially I suspected the problem was caused by adding another SSL site (Django) to the same server as a VirtualHost, at which point SNI comes into play. However, I have tried for a few days disabling SSL on the other site and the problem does not go away.

The first time I reported this problem to my users was 12th April - so it started around that time for sure. This has been steadily happening for the whole time, more or less depending on days.

Apache2 - 2.4.7-1ubuntu4.4
openssl - 1.0.1f-1ubuntu2.11

Anything I could provide for debugging? Attaching "ubuntu-bug apache" output. Is there a good PPA for an updated Apache available? Considering how little I can find information about this problem on the internet (only this old bug really that matches perfectly!), it doesn't seem to be a major issue for many.

I'm going to try prefork anyway as suggested here. If that fails, switching to nginx :P