Product Affected

All releases of JUNOS software prior to June 27, 2002
Medium

Problem

Because of an error in the DNS name-resolution code, improperly formatted DNS messages might cause a buffer overrun in the message parsing routines. This error could enable a remote attacker to execute arbitrary code with the privileges of the program performing the DNS resolution.

This problem is described in more detail in PR/25929 and in the original advisory located at http://www.pine.nl/advisories/pine-cert-20020601.html

Solution

The DNS name-resolution code has been corrected to properly parse all DNS messages, including any padding required. The buffer overflow can no longer be triggered by malformed messages.

All JUNOS software released on or after June 27, 2002 contains the correction for this vulnerability. Juniper Networks strongly recommends that customers update the software on their routers. The fix is included in JUNOS Release 5.1R5 or later, Release 5.2R4 or later, Release 5.3R3 or later, and all releases of JUNOS Release 5.4.

For customers who are unable to upgrade their software, we recommend disabling DNS name resolution. Contact JTAC for instructions.

Severity Assessment

No exploit of this vulnerability is known to exist. However, because the DNS name-resolution code is used in numerous utilities throughout the JUNOS software, many opportunities exist for an attacker to exploit this vulnerability.