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.