Cisco Adaptive Security Appliance Software and Firewall Services Module Software contains a vulnerability that could allow an unauthenticated, remote attacker to bypass security restrictions. Updates are not available.
A vulnerability in the implementation of the time-range object could allow an unauthenticated, remote attacker to bypass access lists that are using the time-range option.
The vulnerability is due to improper implementation of the code for the time-range object, when the periodic command is used. Due to this issue, the time-range object may have no effect. Therefore, depending on the access-list statement (permit or deny), an attacker could bypass the access list. An attacker could exploit this vulnerability by sending traffic through the affected system.
Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.
At the time this alert was first published, the following versions of Cisco products were vulnerable:
Cisco ASA Software versions 8.4.6 and prior
Cisco FWSM versions 4.1.7 and prior
Later versions of Cisco products may also be affected.
Customers are advised to review the bug reports in the vendor announcements section for a current list of affected versions.
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 bypass the access lists that are using the time-range option on a targeted device. Successful exploitation could allow the attacker to gain unauthorized access to sensitive information.
The vulnerability is due to improper implementation of the code for the time-range object when the periodic command is used by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by sending traffic through the affected system. If successful, the attacker could bypass parameters set by the time-range object access list, which could allow the attacker unauthorized access to sensitive information.
Administrators are advised to contact the vendor regarding future updates and releases.
Customers are advised to review the bug reports in the vendor announcements section for guidance on deploying a workaround to mitigate this vulnerability.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to monitor affected systems.
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.