Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition or execute arbitrary code. Updates are available.
Description
Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or execute arbitrary code.
The vulnerability is due to a lack of bounds checking in the Extension Mobility feature of the Cisco Unified Communications Manager Express (CME) component. An unauthenticated, remote attacker could exploit this vulnerability by making a crafted request to the login service for the Extension Mobility feature. Such a request could trigger a buffer overflow that could either cause a DoS condition on the affected system or allow the attacker to execute arbitrary code with elevated privileges.
Cisco has confirmed this vulnerability and released software updates.
Warning Indicators
Cisco has published a list of affected Cisco IOS Software releases in the security advisory. The Vendor Announcements section of this alert contains a link to the advisory.
IntelliShield Analysis
Only devices that are configured to use Cisco Unified CME with the Extension Mobility feature are affected by this vulnerability.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to cause a DoS condition or execute arbitrary code with elevated privileges. If the attacker is able to execute arbitrary code, the result could be a complete system compromise.
Technical Information
The vulnerability is in the login service of the Extension Mobility feature of the Cisco Unified CME component. Only an attacker with a registered phone IP address may exploit this vulnerability. However, if auto registration is enabled, an attacker could use this feature to automatically register a phone IP address. After this has been done, the attacker could exploit this vulnerability by making crafted HTTP requests to the login service of the Extension Mobility feature that could trigger a buffer overflow. When the buffer overflow is triggered, the attacker could either cause a DoS condition on the affected device or execute arbitrary code with elevated privileges. The auto registration feature is enabled by default.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling the Extension Mobility feature to mitigate this vulnerability.
Administrators may consider disabling the auto-registration feature to make it more difficult for an attacker to exploit this vulnerability.
The Cisco Applied Intelligence team has created the following companion document to guide administrators in identifying and mitigating attempts to exploit this vulnerability prior to applying updated software: cisco-amb-20090923-cme
Patches/Software
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via e-mail at tac@cisco.com.
Signatures
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
The security vulnerability applies to the following combinations of products.
Primary Products:
Cisco
IOS
12.4XW Base | 12.4XY Base | 12.4XZ Base | 12.4YA Base
Associated Products:
N/A
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