Sergio Alvarez has reported some vulnerabilities in Avira Antivir, which can be exploited by malicious people to cause a DoS (Denial of Service) or compromise a vulnerable system.

1) An error when processing LZH files can be exploited to cause a buffer overflow via a specially crafted LZH file.

Successful exploitation may allow execution of arbitrary code.

2) A divide-by-zero error when processing UPX-compressed files can be exploited to crash the application via a specially crafted UPX-compressed file.

3) An error when processing TAR files can be exploited to cause an infinite loop consuming available CPU resources.

Solution
Update to AVPack version 7.03.00.09 and Engine version 7.04.00.24. These updates have reportedly been made available since 2007-05-23.

Provided and/or discovered by
Sergio Alvarez, n.runs AG

Changelog
Further details available to Secunia VIM customers

Original Advisory
Avira:
http://forum.antivir-pe.de/thread.php?threadid=22528

n.runs AG:
http://www.nruns.com/advisories/%5Bn.runs-SA-2007.011%5D%20-%20Avira%20Antivir%20Antivirus%20UPX%20parsing%20Divide%20by%20Zero%20Advisory.txt
http://www.nruns.com/advisories/%5Bn.runs-SA-2007.010%5D%20-%20Avira%20Antivir%20Antivirus%20LZH%20parsing%20Arbitrary%20Code%20Execution%20Advisory.txt
http://www.nruns.com/advisories/%5Bn.runs-SA-2007.012%5D%20-%20Avira%20Antivir%20Antivirus%20TAR%20parsing%20Infinite%20Loop%20Advisory.txt

Deep Links
Links available to Secunia VIM customers