Several vulnerabilities have been discovered in the NetScape Portable
Runtime Library, which may lead to the execution of arbitrary code. The
Common Vulnerabilities and Exposures project identifies the following
problems:

CVE-2009-1563
A programming error in the string handling code may lead to the
execution of arbitrary code.
CVE-2009-2463
An integer overflow in the Base64 decoding functions may lead to
the execution of arbitrary code.

The old stable distribution (etch) doesn’t contain nspr.

For the stable distribution (lenny), these problems have been fixed in
version 4.7.1-5.

For the unstable distribution (sid) these problems have been fixed in
version 4.8.2-1.

We recommend that you upgrade your NSPR packages.