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SYNTHESIS OF THE VULNERABILITY

An attacker can create an archive or a program containing a virus,
which is not detected by F-Secure Anti-Virus.

Severity: 2/4

Creation date: 21/03/2012

IMPACTED PRODUCTS

– F-Secure Anti-Virus

DESCRIPTION OF THE VULNERABILITY

Tools extracting archives (RAR, TAR, etc.) accept to extract
archives which are slightly malformed. Systems also accept to
execute programs (ELF, EXE) which are slightly malformed. However,
F-Secure Anti-Virus does not detect viruses contained in these
archives/programs.

An ELF program containing "ustar" at offset 257 bypasses the
detection. [severity:2/4; BID-52581, CVE-2012-1429]

An ELF program containing "\19\04\00\10" at offset 8 bypasses the
detection. [severity:2/4; BID-52589, CVE-2012-1430]

An ELF program containing "\4a\46\49\46" at offset 6 bypasses the
detection. [severity:2/4; BID-52591, CVE-2012-1431]

An EXE program containing a large "class" field bypasses the
detection. [severity:2/4; BID-52598, CVE-2012-1442]

A RAR archive containing "MZ" as its first 2 bytes bypasses the
detection. [severity:1/4; BID-52612, CVE-2012-1443]

A TAR archive with a header containing a large value bypasses the
detection. [severity:1/4; BID-52623, CVE-2012-1459]

A TAR+GZ archive containing two streams bypasses the detection.
[severity:1/4; BID-52626, CVE-2012-1461]

An ELF program with a changed 5th byte bypasses the detection.
[severity:2/4; BID-52614, CVE-2012-1463]

An attacker can therefore create an archive containing a virus
which is not detected by the antivirus, but which is extracted by
extraction tools. The virus is then detected once it has been
extracted on victim’s computer. An attacker can also create a
program, containing a virus which is not detected by the
antivirus, but which can be run by the system.

ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN

http://vigilance.fr/vulnerability/F-Secure-Anti-Virus-bypassing-via-ELF-EXE-RAR-TAR-11477