Vulnerability Note VU#221876

Apple Mac OS X mDNSResponder buffer overflow vulnerability

Original Release date: 25 May 2007 | Last revised: 20 Jun 2007


Apple Mac OS X mDNSresponder contains a buffer overflow vulnerability that may allow an attacker to execute arbitrary code.


mDNS uses IP multicast with DNS to provide the functionality of a DNS server for service discovery in networks that do not have a DNS server. mDNSResponder uses Multicast DNS Service Discovery for service discovery on the local network segment, and Unicast DNS Service Discovery for service discovery outside of the local network.

Bonjour provides zero-confirguation networking for Apple OS X. mDNSResponder is included as a part of Bonjour and runs as a system service. mDNSResponder is a included in OS X and Apple TV.

mDNSResponder contains a buffer overflow vulnerability. This vulnerability occurs in the UPnP IGD (Internet Gateway Device Standardized Device Control Protocol) code that is used to create dynamic port mappings in consumer routers.

Note that an attacker would need to be able to send multicast packets to a vulnerable system to exploit this vulnerability.


An attacker may be able to execute arbitrary code with root privileges, or create a denial of service condition.


Apple has released Security Update 2007-005 to address this issue. Users are encouraged to apply these updates as soon as possible.

Restrict access

Until updates can be applied, creating a firewall rule to restrict access to 5353/udp and 1900/udp may mitigate this vulnerability. See the Apple Support document Creating an Advanced IP Firewall Rule for more information on how to create firewall rules. Note that blocking these ports may cause applications that rely on Bonjour to fail.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Apple Computer, Inc.Affected-25 May 2007
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Thanks to Apple for information that was used in this report. Apple thanks Michael Lynn of Juniper Networks for reporting this issue.

This document was written by Ryan Giobbi.

Other Information

  • CVE IDs: CVE-2007-2386
  • Date Public: 24 May 2007
  • Date First Published: 25 May 2007
  • Date Last Updated: 20 Jun 2007
  • Severity Metric: 6.09
  • Document Revision: 13


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