My initial setup of Ring Camera’s with my Firewalla was pretty lacklustre! They were isolated in a device group from all other networks, but had free outbound access to the internet. So, at first I got a few alerts for domains like ring.com and added these as allow rules. Everything was generally good, but I constantly got “unusual upload” alerts on the Firewalla for my Ring cameras, these were always Ireland based IP’s associated with Amazon. Each time I got an alert, I added it to the mute/ exclusion list, but this was burdensome!
Then as mentioned in my last post (https://blog.oholics.net/s3-amazonaws-com-dns-resolution-and-firewalla/), I started locking stuff down, including my Ring cameras, following the same process as I used for my PiHole. I googled “allowed IP addresses for Ring cameras” previously and got the gist that there is no easy way.
After the success I had with my previous use of Target Lists on the Firewalla , I looked to use the same approach for this issue. After locking down the device group, I noted that the target IP’s were nearly all West EU based IP’s for the AMAZON service, so needed to add some more arguments to my jq query – I needed the ranges for the AMAZON service in eu-west-1, eu-west-2 and eu-west-3. To do so, I used the test argument, as follows:
However, after I had the files containing the ranges, I realised that there was some duplication between the sets; some Amazon services share IP ranges, where the AMAZON service list covered EC2 as well. I added these ranges to new Target Lists using the Firewalla web interface.
Back on my phone, I added rules to allow traffic to the IP ranges in these allow lists:
And then added those same Target Lists to the mute list for Abnormal Uploads, targeting the Ring Cameras group only.
Since I made these changes, I’m no longer seeing any blocked outbound traffic from my Ring cameras or any alerts relating to Abnormal Uploads 🙂
A few years ago I bought a Firewalla Gold device to help provide some additional protection to my home network, but more importantly to control what my kids had access to and when they had internet access.
My initial setup was fairly basic, but did the job. I’ve also been running PiHole and Unbound on a Raspberry Pi Zero 2, which has been very effective at black-holing advertising and other undesirable DNS traffic.
Over the Christmas/ new year holiday, I got hold of a Cisco switch which was capable of VLAN tagging, so set about having a bit of a tidy up/ isolation of devices/ networks.
I made the following changes:
Created a VLAN for the PiHole, the Zero 2 is hardwired via an Amazon Firestick network adaptor.
Created a device group on the Firewalla, which only contains that Zero 2.
Allowed incoming port 53 connections from all internal networks/ VLANs to the Zero 2.
Blocked all inbound and outbound traffic from the PiHole VLAN.
Permitted port 53 outbound traffic (public) from the Zero 2.
Now the network is isolated, I updated gravity on the PiHole to see what is now blocked, then added allow rules for all desired traffic.
One allow rule added was for s3.amazonaws.com as two of the blocklists were hosted in S3 buckets. That is the back story, now onto the problem and my solution.
The problem: When Gravity ran on the PiHole, it always failed to get the two blocklists that were hosted on s3.amazonaws.com, even though I had an allow rule on the Firewalla for that domain.
Why: Amazon services are massive and widely distributed! Resolution of DNS will provide a different set of IP’s every time you try. The image below shows my Pihole on the left and the Firewalla console on the right:
The Firewalla was supposed to learn the IP’s of the domain to honour the allow rule. However, after making all the changes requested in my support ticket with Firewalla, the issue remained. Note that some IP’s were trusted and (most) others were not, see:
So the fix… Initially I figured that I would just pick a “trusted” IP and add it to the PiHole local DNS, that worked but wasn’t very resilient! So, then I looked at how I could tell Firewalla to trust all IP’s associated to the S2 namespace.
On a recent project, I needed a reliable and repeatable method of creating Azure AD service principles for use with Azure DevOps and Azure Sentinel, among other things. I also needed to apply Azure roles to these service principles at different levels of the hierarchy, be that root management group, sub management group or subscription. All examples assume that the az module is already installed.
Create the service principle:
For the SP that I created for the DevOps team, I needed to give it the Owner role at the root level:
Additionally, I discovered that if you delete a SP prior to removing its roles, you end up with orphaned references in the resource level role assignments. Where these were inherited from the root level and I had no GUI visibility of that level, I had to use PowerShell to tidy up. Assuming that you don’t have a record of the ObjectID of the deleted SP, get all role assignments with:
If we look at the parameters from the command “Get-Help Set-Label -Detailed”, we see:
So the parameters that I wanted to set were LabelActions and Conditions. LabelActions configure headers, footers and watermarks, while Conditions define the O365 Sensitivity Types that are applied to a label.
The documentation for how to do this was non-existent, apart from some cryptic “Exchange” docs detailing how to define “MultiValuedProperty”, I was fairly stumped. I ended up up backwards engineering the configuration by setting it in the GUI, then capturing the Label in PowerShell. Once captured, look at the configuration of “Conditions” or LabelActions to see how those Properties are defined in the case of Unified Labelling.
The following script details how this all works together to create something useful. It provisions a new Label named “My Label”, with a green colour. Then it applies a header “HeaderText” and footer “FooterText” and then a watermark “WatermarkText”, all in Black and font size 10. Lastly it applies the O365 sensitivity types “ABA Routing Number” and “Argentina National Identity (DNI) Number” to the label, in Recommended mode.
Also covered for reference is the creation of a sub-label “My Sub Label”, beneath “My Label”.
Once the labels are defined, we need to publish them with a policy. First create the policy, providing the label names and scope, then apply any required advanced settings to the policy.
Note the script below assumes that the last session was ended, we need to login again – else just continue the previous session.
Finally, the documentation states that label priority follows this rule: “A lower integer value indicates a higher priority, the value 0 is the highest priority“. However, in practice the opposite is true.
Say for example you have the following labels “Public”, “Internal” and “Secret”; for the advanced setting “RequireDowngradeJustification” to apply as expected, (following the documentation) you would set “Secret” = 0, “Internal” = 1 and “Public” = 2. This actually has the opposite effect, making a downgrade from Secret to Public not raise the justification dialog box, while Public to Secret is classed as a downgrade; also the order of labels in the toolbar is the wrong way around. So the proper order should be: “Public” = 0, “Internal” = 1 and “Secret” = 2.
Additionally, the priority can get quite messed up if you have any existing labels or if you deploy the labels in the wrong order. Continuing from my example, but also throwing in 2 sub labels per top level label….
First connect (or continue the existing session), then get the current priorities. If they don’t match the output shown in the script, then start fixing them! Start by interactively running the priority settings for the top level labels (only do those that are not correct), starting with the highest values and working down. Check the priorities after each change.
Once the top level labels are correct, start fixing the sub labels (assuming they are not right). Reset them individually, again setting the highest value first, check the priorities after each change. Rinse and repeat until the order is as desired, then go have a G & T 🙂
Another case of “I’ve done this before, but never wrote it down”, so revisiting this took far longer than it should have. But now it is here, that won’t happen again.. right?? I’ll probably never need it again now… typical..
OK, so a straight forward non-secure ldapsearch command, obtains everything (-h can be IP or FQDN):
For both TLS and SSL on port 636, using the IP as the host (-h or -H) fails. It MUST use the FQDN of the target system. Why? because the certificate on the DC only refers to the FQDN of the server.
SSL/ 636 – The error “Can’t contact LDAP server (-1)” was really stumping me as there is little to go on in the error message. Doing a network capture, just shows the handshake start, but the DC ultimately just says “Go Away!”. It resets the connection attempt.
A few things learnt:
1. Using -h FQDN and -p 636 results in Can’t contact LDAP server (-1) (the URI method above must be used)
Additionally, for TLS connection. Using the IP address of the DC, resulted in a different, but much more helpful error message:
ldapsearch -h 192.168.1.201 -p 389 -b “DC=oholics,DC=net” -D “CN=svc-LDAPBind,OU=ServiceAccounts,DC=oholics,DC=net” -w “<MyPass>” -Z ldap_start_tls: Connect error (-11) additional info: TLS: hostname does not match CN in peer certificate
Also, where a Domain Controller has the setting “Domain controller: LDAP server signing requirements” set to Require signing. When trying to initiate an insecure LDAP query with ldapsearch, it fails as follows:
ldapsearch -h 192.168.1.201 -p 389 -b “DC=oholics,DC=net” -D “CN=svc-LDAPBind,OU=ServiceAccounts,DC=oholics,DC=net” -w “<MyPass>” ldap_bind: Strong(er) authentication required (8) additional info: 00002028: LdapErr: DSID-0C090257, comment: The server requires binds to turn on integrity checking if SSL\TLS are not already active on the connection, data 0, v2580
If you don’t manage security logs by regularly backing them up and clearing them, you risk losing important historical information. Additionally, running a LogParser query against a large, unmanaged security event log takes a long time.
The below script is designed to be run daily at the end of the day to backup the security event log on a Domain Controller and then clear its contents. Additionally, the logs are archived off to two windows shares to allow for long term storage.
Make sure that the security event log maximum size is increased to a high enough level to ensure that none of the days logs get overwritten. Judging that size will depend on the number of events per day or alternatively just set to “do not overwrite events”.
Just digging something up that I used to use regularly to look for logon events related to a certain username (samAccountName). Thought I’d regurgitate them here for “the next time..”
Three different SQL queries for three different use cases:
Case 1. I know that the logon event that I’m looking for occurred on DC01.oholics.net, I’m therefore going to interrogate the live DC log. The primary username I’m looking for is “jon”, a secondary name shown as “dave”. This could be replaced by a junk string if I’m only really looking for “jon”, or just trim the query (up to you.. ).
Case 2. In my domain, there are three domain controllers, I’m not sure where the logon events happened, so as in Case 1 I search the live DC logs, but this time searching all DC’s logs.
Case 3. I have three months of backed up logs to search through (in C:\TEMP\Logs) for all logon events for samAccount name “jon” (and optionally “dave”, as above). I may splurge out the script that I used to use to backup and clear the event logs next, that could be useful again – I’ve got to clean it first.