Product Affected

JUNOS Internet software Releases 5.2R1.4, 5.2R2.3, 5.2R3.4, 5.2R4.4, 5.3R1.2, 5.3R2.4, 5.3R3.3, and 5.4R1.4
Medium

Problem

In the releases affected, the DNS name-resolution code might attempt to read beyond the end of the buffer. Various programs that include the name-resolution code can experience bus errors or segment violation faults.

This problem is described in more detail at http://www.kb.cert.org/vuls/id/738331 and is documented as PR/27529.

Solution

The DNS name resolution code has been updated to properly check the returned length of its buffer.

Customers should install an updated release of JUNOS software. All releases of JUNOS software built on or after August 22, 2002, contain the fix.

Severity Assessment

Excessively long fully qualified host names can be provided by any name server. No direct access to or privileges on the router are required to launch this denial-of-service (DoS) attack.