Several vulnerabilities have been discovered in the Network Security Service libraries. The Common Vulnerabilities and Exposures project identifies the following problems:
Moxie Marlinspike discovered that a buffer overflow in the regular expression parser could lead to the execution of arbitrary code.
Dan Kaminsky discovered that NULL characters in certificate names could lead to man-in-the-middle attacks by tricking the user into accepting a rogue certificate.
Certificates with MD2 hash signatures are no longer accepted since they're no longer considered cryptograhically secure.
The old stable distribution (etch) doesn't contain nss.
For the stable distribution (lenny), these problems have been fixed in version 22.214.171.124-0lenny1.
For the unstable distribution (sid), these problems have been fixed in version 126.96.36.199-1.
We recommend that you upgrade your nss packages.