Cisco Adaptive Security Appliance (ASA) Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the implementation of the function used to validate digital certificates for authentication could allow an unauthenticated, remote attacker to cause a reload of an affected device.
This vulnerability is due to an implementation error in the code that validates the digital certificates used during authentication. An attacker could exploit this vulnerability by using a crafted certificate to trigger an authentication operation on an affected device.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
The following releases of Cisco ASA Software are affected by this vulnerability:
Cisco ASA Releases prior to 7.2(5.10)
Cisco ASA Releases prior to 8.0(5.31)
Cisco ASA Releases prior to 8.2(5.38)
Cisco ASA Releases prior to 8.3(2.37)
Cisco ASA Releases prior to 8.4(5)
Cisco ASA Releases prior to 8.5(1.17)
Cisco ASA Releases prior to 8.6(1.10)
Cisco ASA Releases prior to 8.7(1.3)
To exploit this vulnerability, an attacker would need to send a crafted certificate to trigger an authentication operation on an affected device. In a typical network configuration, such devices are placed on trusted, internal networks. This access requirement could limit the possibility 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.
An unauthenticated, remote attacker could exploit this vulnerability to cause the targeted device to reload, resulting in a denial of service (DoS) condition. Repeated exploitation could result in a sustained DoS condition.
The vulnerability is due to an implementation error in the affected software that validates digital certificates used during authentication.
An unauthenticated, remote attacker could exploit this vulnerability by using a crafted certificate to trigger an authentication operation on a targeted device. Successful exploitation could cause the affected device to reload, resulting in 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 implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to monitor affected systems.
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 firstname.lastname@example.org.
The security vulnerability applies to the following combinations of products.
Cisco Adaptive Security Appliance (ASA) Software
8.2 .1, .2, .3, .4, .5
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