Cisco Adaptive Security Appliance Software contains a vulnerability that could allow an authenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the clientless SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause an affected system to reload.
The vulnerability is due to a stack overflow while browsing internal resources via the clientless SSL VPN portal when the same-security-traffic permit intra-interfaceand management-access commands are configured. An attacker could exploit this vulnerability by accessing a crafted URL through the SSL VPN portal. An exploit could allow the attacker to reload the affected system and create a denial of service (DoS) condition.
Cisco has confirmed the vulnerability in a security notice and released software updates.
At the time this alert was first published, Cisco ASA Software versions 9.1.3 and prior were vulnerable. Later releases of Cisco ASA Software may also be vulnerable.
To exploit this vulnerability, an attacker must authenticate to an affected device. This access requirement decreases the likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
Cisco has released a security notice at the following link: CVE-2013-5551
Customers are advised to consult Cisco bug ID CSCui51199 or the most complete list of affected product versions.
An authenticated, remote attacker could exploit this vulnerability to cause an affected device to reload, resulting in a DoS condition.
The vulnerability is due to a stack overflow while browsing internal resources via the clientless SSL VPN portal when an affected device is configured with the same-security-traffic permitintra-interface and management-access commands.
An authenticated, remote attacker could exploit this vulnerability by accessing a crafted URL through the SSL VPN portal. An exploit could allow the attacker to reload the affected system and create a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at firstname.lastname@example.org for assistance.
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.