Snort 2.9.5.6 pkg v3.0.4 Update – Release notes and change log

bmeeks

@BBcan17:

@bmeeks:

You are probably seeing "history".

So the alert should have happened in the past, you disabled the rule, but the original entry is still in the alerts log and will be read and shown in the list. To see if my theory is correct, reduce the number of alerts to display to something like 3 or 4 and see if the disabled ones disappear. If not post back.

These are fresh events. See attached png files. Those rules have been disabled for a long time now.

OK, one more question. Did you try manually restarting Snort after disabling the rule? That should not be required, but maybe something is not working with live reload. Also, did you disable the rule from the new ALERTS tab icon or from the RULES tab? If on the RULES tab, you need to click APPLY after disabling the rule in order for a new rule set to build.

I will test this in a virtual machine again. It was working (or at least I thought it was working… :-[).

Bill

BBcan177

Hi Bill,

I didn't add or remove any rules today. Those rules were disabled months ago. :(

bmeeks

@BBcan17:

Hi Bill,

I didn't add or remove any rules today. Those rules were disabled months ago. :(

Hmm…OK, one more question. Look in your config.xml file using Diagnostics…Edit File. The path to the file is /conf/config.xml. Scroll down and find all the Snort parameters. The section title will start with <snortglobal>. You will see collections of data for each configured interface. For the interface in question, find the tag element for <rule_sid_off>and look at the values stored there. You should have pairs of numbers separated colons. These are the GID:SID values for the rule. Each GID:SID pair should be delimited by " || " double-pipe symbols. Let me know if anything other than what I described is in there.

It's late where I am, so I will test this in a VM tomorrow and see if I goofed it up someplace.

Bill</rule_sid_off></snortglobal>

BBcan177

Hi Bill,

It looks ok to me…

Let me know if you want me to send it to you?

Thanks.

VipIT

Hi,

I updated the snort package today, but when starting snort with the block option I get the following error:
"Feb 20 10:09:13 snort[7254]: FATAL ERROR: pf.conf => Table snort2c don't exists in packet filter: No such file or directory"

I searched the net, and found a previous post about the same issue but for an older version, so the resolution is not the same.
Can you please tell me how to make this work again? I highly rely on the auto block option as we see a lot of russian botnets trying to attack or scan our servers.

PS I tried reinstalling the package and uninstalling and installing it again. Although with saving options, as I deselected some of the rules

Thanks in advance
K.R.

Ruben Vanhoutte

bmeeks

@VipIT:

Hi,

I updated the snort package today, but when starting snort with the block option I get the following error:
"Feb 20 10:09:13 snort[7254]: FATAL ERROR: pf.conf => Table snort2c don't exists in packet filter: No such file or directory"

I searched the net, and found a previous post about the same issue but for an older version, so the resolution is not the same.
Can you please tell me how to make this work again? I highly rely on the auto block option as we see a lot of russian botnets trying to attack or scan our servers.

PS I tried reinstalling the package and uninstalling and installing it again. Although with saving options, as I deselected some of the rules

Thanks in advance
K.R.

Ruben Vanhoutte

Whoa! That is a strange error message. What version of pfSense are you running? Seems like maybe an old one? The <snort2c>alias table it is complaining about is part of the base pfSense install and is not added or removed by the Snort package. The fact that table is reported as missing seems to indicate maybe you have a very old pfSense version.

If you have version older than 2.0.x, then I strongly recommend updating. If you have a version equal to or newer than 2.0.x, then something very bad has happened to the installation and a complete re-install is likely required to fix it.

Bill</snort2c>

A Former User

Reporting that the rule disable button on the alerts tab works as expected.

Preprocessor rules are also working as expected. It might be me, or the reduced suppression list but the systems feel faster.

Over and out :P

bmeeks

@jflsakfja:

Reporting that the rule disable button on the alerts tab works as expected.

Preprocessor rules are also working as expected. It might be me, or the reduced suppression list but the systems feel faster.

Over and out :P

Thanks for the feedback. I was investigating BBcan17's issue posted above where he said a disabled rule was still firing for him, and was so far I am unable to reproduce. Your confirmation the rules disable feature is working for you as intended is helpful.

On the faster front, could be the update to Snort 2.9.5.6 is helping as well. The Snort VRT folks are still making various "under-the-hood" updates now and then.

Bill

bmeeks

@BBcan17:

Hi Bill,

It looks ok to me…

Let me know if you want me to send it to you?

Thanks.

BBcan17:

Quick question from something I just noticed in your screenshots. Are you running both Emerging Threats Pro and Emerging Threats Open rules concurrently? It looks like both have generated an alert from your screenshots, and that really should not be possible. The GUI is supposed to lock out one when the other is selected (on the GLOBAL SETTINGS tab). The code is also supposed to remove ET Open rules if you enable ET Pro, and vice versa.

If you are in fact running both rule sets, then you could very well have duplicate SIDs. The GUI code is not set up to handle this as that would be an unexpected occurrence based on locking out ET Open when ET Pro is selected, or locking out ET Pro when ET Open is selected. The disable SID code will basically just find and disable the first occurrence of the SID in the rules array when searching. So it could be disabling the ET Pro SID for one disabled ET Open rule, and then the ET Open SID for another ET Pro one. Does what I'm saying make sense?

Reply back and let me know if you are in fact using both rule sets (and how you managed to enable them if you are). By the way, the Emerging Threats Pro rules contain all of the ET Open rules and then extra "Pro Rules". It's the extra Pro rules that you pay for. My understanding is there is no benefit to running both sets of Emerging Threats rules.

Bill

VipIT

@bmeeks:

@VipIT:

Hi,

I updated the snort package today, but when starting snort with the block option I get the following error:
"Feb 20 10:09:13 snort[7254]: FATAL ERROR: pf.conf => Table snort2c don't exists in packet filter: No such file or directory"

I searched the net, and found a previous post about the same issue but for an older version, so the resolution is not the same.
Can you please tell me how to make this work again? I highly rely on the auto block option as we see a lot of russian botnets trying to attack or scan our servers.

PS I tried reinstalling the package and uninstalling and installing it again. Although with saving options, as I deselected some of the rules

Thanks in advance
K.R.

Ruben Vanhoutte

Whoa! That is a strange error message. What version of pfSense are you running? Seems like maybe an old one? The <snort2c>alias table it is complaining about is part of the base pfSense install and is not added or removed by the Snort package. The fact that table is reported as missing seems to indicate maybe you have a very old pfSense version.

If you have version older than 2.0.x, then I strongly recommend updating. If you have a version equal to or newer than 2.0.x, then something very bad has happened to the installation and a complete re-install is likely required to fix it.

Bill</snort2c>

Hi Bill,

I solved it. apparently the problem was situated in my aliasses. I had an 'URL table' alias with around 4300 IP addresses that needed to be blocked.
I noticed that the block rules for that alias wasn't working and all firewall rules were disabled to the point everything was any-any allowed.
Removing that Alias caused everything to work again. So apparently that single alias with >4000 IP's broke the whole firewall..

bmeeks

@VipIT:

@bmeeks:

@VipIT:

Hi,

I updated the snort package today, but when starting snort with the block option I get the following error:
"Feb 20 10:09:13 snort[7254]: FATAL ERROR: pf.conf => Table snort2c don't exists in packet filter: No such file or directory"

I searched the net, and found a previous post about the same issue but for an older version, so the resolution is not the same.
Can you please tell me how to make this work again? I highly rely on the auto block option as we see a lot of russian botnets trying to attack or scan our servers.

PS I tried reinstalling the package and uninstalling and installing it again. Although with saving options, as I deselected some of the rules

Thanks in advance
K.R.

Ruben Vanhoutte

Whoa! That is a strange error message. What version of pfSense are you running? Seems like maybe an old one? The <snort2c>alias table it is complaining about is part of the base pfSense install and is not added or removed by the Snort package. The fact that table is reported as missing seems to indicate maybe you have a very old pfSense version.

If you have version older than 2.0.x, then I strongly recommend updating. If you have a version equal to or newer than 2.0.x, then something very bad has happened to the installation and a complete re-install is likely required to fix it.

Bill</snort2c>

Hi Bill,

I solved it. apparently the problem was situated in my aliasses. I had an 'URL table' alias with around 4300 IP addresses that needed to be blocked.
I noticed that the block rules for that alias wasn't working and all firewall rules were disabled to the point everything was any-any allowed.
Removing that Alias caused everything to work again. So apparently that single alias with >4000 IP's broke the whole firewall..

Glad you sorted it out. I think I've seen a few others posting in other sub-forums about problems with large numbers of IPs in alias tables on pfSense. You could post the issue in the Firewall section of the Support Forum and see if any of the folks in there can help.

Bill

BBcan177

@bmeeks:

Quick question from something I just noticed in your screenshots. Are you running both Emerging Threats Pro and Emerging Threats Open rules concurrently? It looks like both have generated an alert from your screenshots, and that really should not be possible.

Reply back and let me know if you are in fact using both rule sets (and how you managed to enable them if you are). By the way, the Emerging Threats Pro rules contain all of the ET Open rules and then extra "Pro Rules". It's the extra Pro rules that you pay for. My understanding is there is no benefit to running both sets of Emerging Threats rules.

Bill

Hi Bill, I am using VT Pro and Snort VRT (pd).

I did noticed a few days ago that one of my alias tables (less than 100 ips) duplicated 3 times in the Alias Lists. I had to rename the 2 duplicates and than it allowed me to delete it.

I also am noticing that one of the rules "ET POLICY curl User-Agent Outbound" which was disabled months ago. Keeps blocking traffic. I have tried to add a suppress but it still blocks any traffic. I've tried to remove the block from the table and restart Snort without success.

I do notice that the GUI is a lot quicker to respond than previously.

Rules.png_thumb

A Former User

@BBcan17:

I also am noticing that one of the rules "ET POLICY curl User-Agent Outbound" which was disabled months ago. Keeps blocking traffic. I have tried to add a suppress but it still blocks any traffic. I've tried to remove the block from the table and restart Snort without success.

Just tested (curl ifconfig.me) and the rule did not fire up an alert. Are you sure it's disabled/suppressed?

EDIT: On a side note, the pcaps in /var/log/snort/$interface don't appear to be timestamped correctly, or certain captures are not logged. I'm looking for a specific capture to investigate an IMAP unknown response and an IMAP unknown command for a client of mine and cannot find it.

EDIT2: greping the files for the IP shows all the entries in the alert file, but not in other files (snort.log.xxxxxxxxx), so I'm guessing it wasn't logged after all.

BBcan177

Hi Bill,

I have uninstalled the Snort package and re-installed and it looks like its back to normal? I will keep you posted.

After it was re-installed, while it was enabling the Interfaces in the back ground, i noticed the first alert was from a "Disabled" Rule. but the balance of the alerts since Snort
was fully enabled on both interfaces are all from "Enabled" Rules only.

The "ET POLICY curl User-Agent Outbound" rule is also not being blocked since the re-install as per my last post.

I will have to let it run for a bit to know for sure…. ;)

Thanks.

BBcan177

@jflsakfja:

Just tested (curl ifconfig.me) and the rule did not fire up an alert. Are you sure it's disabled/suppressed?

That rule was disabled and the alert was greyed out in the Alerts Tab. I also had it in the suppress.

Re-Install seems to have fixed it.

bmeeks

@BBcan17:

Hi Bill,

I have uninstalled the Snort package and re-installed and it looks like its back to normal? I will keep you posted.

After it was re-installed, while it was enabling the Interfaces in the back ground, i noticed the first alert was from a "Disabled" Rule. but the balance of the alerts since Snort
was fully enabled on both interfaces are all from "Enabled" Rules only.

The "ET POLICY curl User-Agent Outbound" rule is also not being blocked since the re-install as per my last post.

I will have to let it run for a bit to know for sure…. ;)

Thanks.

OK. Sounds like something got sort of messed up at some point. Glad the reinstall seems to have fixed things for you. I tested disabling rules this morning, and they do in fact get completely removed from the snort.rules file where all the active rules go. You will find this file in the interface directory such as /usr/pbi/snort-amd64/etc/snort/snort_xxxxx_em0/rules (where xxxxx is the UUID for the interface). So if you want to be sure a particular rule is not being used, just grep for it in that file. If not there, then the running Snort interface with the same UUID can't be using it since it reads the rules to enforce from that file.

Bill

A Former User

Where can I find the recognized IMAP commands? been searching for a while and couldn't find them in a file. Need to check a packet capture against the known commands to see what's causing the rule to fire an alert.

bmeeks

@jflsakfja:

Where can I find the recognized IMAP commands? been searching for a while and couldn't find them in a file. Need to check a packet capture against the known commands to see what's causing the rule to fire an alert.

Should be listed in the snort.conf file for the interface. Assuming a pfSense 2.1 64-bit build, the path would be:

/usr/pbi/snort-amd64/etc/snort/snort_xxxxx_em0/snort.conf

Modify the path with "i-386" if a 32-bit machine. The "xxxx" is a UUID that is unique to each interface, and the "em0" in my example is the physical interface name. It may be different on your hardware.

For now the SMTP and IMAP commands are not user-editable, and any changes you make manually in the file will be overwritten at the next save of any configuration change or if Snort restarts.

You can, if you want to, disable the IMAP preprocessor completely on the PREPROCESSORS tab, and then go to the INTERFACE tab for the specific interface and type all the IMAP preprocessor configuration info manually into the Advanced Pass-Through box at the bottom of the page.

Bill

A Former User

# IMAP preprocessor #
preprocessor imap: \
	ports { 143 } \
	memcap 1310700 \
	qp_decode_depth 0 \
	b64_decode_depth 0 \
	bitenc_decode_depth 0

That's the only things included for imap. so are all the imap commands missing?

bmeeks

@jflsakfja:

# IMAP preprocessor #
preprocessor imap: \
	ports { 143 } \
	memcap 1310700 \
	qp_decode_depth 0 \
	b64_decode_depth 0 \
	bitenc_decode_depth 0
That's the only things included for imap. so are all the imap commands missing?

Yeah, that's what is used in the configuration. I tried to mimic what is in the default snort.conf included in the source tarball, but I don't remember specifically if I looked into the IMAP preprocessor in much detail. If you have some suggested content for that or the other preprocessors, put it together and send to me in a PM (or post it here). I will try to incorporate it into a subsequent release. Just remember to stay sort of general in nature remembering that the goal is for Snort to work for the majority of users with the out-of-the-box settings.

Bill