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Author Topic: VACRON firmware format  (Read 609 times)

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July 27, 2017, 05:12:16 am
Hi,

I have this IP camera from VACRON.com, I checked their firmware and couldn't find anything about it. I mean it either encypted or compressed.

Suppose it's possible to unpack/decrypt firmware. Would it be possible to modify the linux inside it and upload it back?

http://www.vacron.com/IPsurveillance_support1.html
http://www.vacron.com.tw/download/ipcam%20softward/VIG-SONY-2MP-DS&US-7XX_PID100_Ver1.0.21-1203.bldsysapp.pack.rar

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July 28, 2017, 01:16:26 am
I downloaded the rar file, unpacked and took a cursory look at the bin file.

Looks like its possibly encrypted or compressed post header, as I don't see many FF's or 00 strings in the file after the initial header.
strings also doesn't show any readable text, which ties in with it being compressed or encrypted.

A scan with binwalk ( http://binwalk.googlecode.com ) to see if it finds any recognizable FS or compression in there shows nothing.

I'm guessing its probably encrypted with some custom method.

You'd need more firmware files to look at in order to proceed.

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July 28, 2017, 07:36:03 am
I grabbed some other files they provide for other cams. One of those files was JFFS, from which I got "update.cgi", but couldn't understand the algoright for it. Anyway, they seem to pack kernel and fs into that binary file. Attached some flowcharts from IDA and original update.cgi

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July 28, 2017, 01:30:05 pm
I wish I could afford IDA, that was actually moderately useful.

You can't assume/guarantee that the update /upgrade mechanism will be the same for each camera though.

Looks like it loads the file via web interface into ram, writes to /tmp then does some compares to see if valid.
I'd check the .bin file you first gave to see if it passes their compare process.