Vulnerability Note VU#221876

Apple Mac OS X mDNSResponder buffer overflow vulnerability

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.

II. Impact

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

http://docs.info.apple.com/article.html?artnum=305530
http://developer.apple.com/networking/bonjour/faq.html
http://docs.info.apple.com/article.html?path=ServerAdmin/10.4/en/c4ns11.html
http://www.apple.com/appletv/
http://www.iss.net/threats/264.html
http://www.upnp.org/standardizeddcps/igd.asp
http://en.wikipedia.org/wiki/IP_Multicast
http://docs.info.apple.com/article.html?artnum=305631

Credit

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

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