Archive Formats Kill Antivirus Products 115
nemiloc sends us to the F-Secure blog for breaking news about widespread vulnerabilities in programs that process archive files: "The Secure Programming Group at Oulu University has created a collection of malformed archive files. These archive files break and crash products from at least 40 vendors — including several antivirus vendors... including us." Here is test material from OUSPG and a joint advisory from Finnish and English security organizations. It isn't news that security products can have have security vulnerabilities. What makes this advisory important is that antivirus software is a perfect target. It is run in critical places with high privileges and auto-updates to keep versions coherent.
Re:Secure Platform without Anti-virus (Score:3, Interesting)
Re:There's breakage and there's breakage (Score:5, Interesting)
Very little software in practice is that smart. But with AV, you know you're at war with the file you're scanning. Any AV vendor caught by this should be embarrased.
Bad programming (Score:3, Interesting)
Re:Secure Platform without Anti-virus (Score:2, Interesting)
That's been going on for ages!!! (Score:5, Interesting)
The next version did fix that finally...for pkzip.
Using social engineering that is rather inept by todays standards I convinced several people on usenet to not read the text telling that it could cause problems but to just blindly open the doubly zipped file (it gets smaller when doubly zipped a certain way so I made it 2G to start).
I did the same thing with PGP which could allow one to kill an encrypted anonymous remailer and I also nailed several people by posting the PGP message with a passphrase. PGP compresses files prior to encryption. I didn't mess with the remailer without asking permission. The person running it was a bit surprised.
Linux commands:
dd if=/dev/zero of=hi bs=1024 count=200512
zip hi.zip hi
Result -rw-r--r-- 1 bogus bogus 199411 2008-13-48 18:04 hi.zip
zip -9 ho.zip hi.zip
Result -rw-r--r-- 1 bogus bogus 846 2008-30-81 18:13 ho.zip
I'm not sure why but using -9 to start does not make the original super small it only works the second time.
If you want to assault a fractal compressor, just insert a non-finite automata and have at them. You get points if it's video and draws frame after frame of something inappropriate.