Stephen Gran discovered that malformed base64-encoded MIME attachments can lead to denial of service through a null pointer dereference.
For the stable distribution (sarge) this problem has been fixed in version 0.84-2.sarge.12.
For the upcoming stable distribution (etch) this problem has been fixed in version 0.86-1.
For the unstable distribution (sid) this problem has been fixed in version 0.86-1.
We recommend that you upgrade your clamav package.
MD5 checksums of the listed files are available in the original advisory.