Apple iChat fails to properly handle crafted TXT key hashes

Overview

A vulnerability in the way Apple iChat handles specially crafted TXT key hashes could lead to denial of service.

Description

Apple iChat is an instant message client for Apple Mac OS X. Apple iChat Agent is a back-end process that manages iChat sessions and available contacts. Apple Bounjour is a service provided with Apple Mac OS X that facilitates automatic discovery of computers, devices, and services on IP networks. The iChat Agent uses Bonjour to discover available contacts. The Apple iChat Agent contains a vulnerability that could be exploited when it attempts to handle specially crafted TXT key hashes received via Bonjour messages. According to MOAB-29-01-2007:

This will instantly cause a SIGTRAP signal to be sent to the process, causing a so-called ‘crash’. Further attempts to launch iChat Bonjour functionality again will fail as mDNSResponder keeps the crafted record (and restarting it will be necessary).

---

Impact

A remote, unauthenticated attacker on the same multicast network may be able to cause iChat to crash, thereby creating a denial-of-service condition.

---

Solution

Update

Apple has released an update to address this issue. See Apple Security Update 2007-002.

---

Vendor Information

836024

Filter by status: All Affected Not Affected Unknown

Filter by content: __ Additional information available

__ Sort by: Status Alphabetical

Expand all

Javascript is disabled. Click here to view vendors.

Apple Computer, Inc. __ Affected

Updated: February 16, 2007

Status

Affected

Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

Refer to Apple Security Update 2007-002.

If you have feedback, comments, or additional information about this vulnerability, please send us [email](<mailto:[email protected]?Subject=VU%23836024 Feedback>).

CVSS Metrics

Group	Score	Vector
Base
Temporal
Environmental

References

• <http://projects.info-pull.com/moab/MOAB-29-01-2007.html&gt;
• <http://secunia.com/advisories/23945/&gt;
• <http://docs.info.apple.com/article.html?artnum=305102&gt;
• <http://secunia.com/advisories/24198/&gt;
• <http://www.apple.com/macosx/features/ichat/&gt;
• <http://developer.apple.com/networking/bonjour/index.html&gt;
• <http://securitytracker.com/alerts/2007/Feb/1017661.html&gt;
• <http://www.securityfocus.com/bid/22304&gt;

Acknowledgements

This issue was reported by LMH in MOAB-29-01-2007.

This document was written by Chris Taschner.

Other Information

CVE IDs:	CVE-2007-0710
Severity Metric:	2.48 Date Public: