Marcus Meissner discovered that attackers can trigger a buffer overflow in the path handling code by creating or abusing existing symlinks, which may lead to the execution of arbitrary code.
This vulnerability isn't present in the kernel NFS server.
This update includes a bugfix for attribute handling of symlinks. This fix does not have security implications, but at the time when this DSA was prepared it was already queued for the next stable point release, so we decided to include it beforehand.
For the old stable distribution (woody) this problem has been fixed in version 2.2beta47-12woody1.
For the stable distribution (sarge) this problem has been fixed in version 2.2beta47-20sarge2.
For the unstable distribution (sid) this problem has been fixed in version 2.2beta47-22.
We recommend that you upgrade your nfs-user-server package.