Fix out of bounds reads in packet parsing #2954
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Consuming bytes reduces the number of bytes left. Fix this for PAD1 case where it was increased instead.
PacketParser::parse_packet code does not account for an edge case where a RAW packet is added at the end of this_packet[], causing an out of bounds read in the array processing code that follows.
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Thanks for these fixes! The The |
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Should be straightforward. I do not think these have any security impact, but reading out of bounds isn't nice.
This was found with AFL and the test code included in last commit.
Btw, while doing this, I have also come across another out of bounds read in DNS code, which is already described in https://tomerfry.github.io/2023/05/26/Fuzzing-NMAP-With-AFL++.html
From my experiments it's an over-read in input buffer to DNS::Packet::parseFromBuffer(). I haven't analysed it enough to figure out the root cause, hence no patch.