Cisco ASA Software for the 1000V Cloud Firewall contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Cisco ASA Software for the 1000V Cloud Firewall versions 8.7.1 and 18.104.22.168 contain a vulnerability that could allow an unauthenticated, remote attacker to cause a reload of the Cisco 1000V Cloud Firewall.
The vulnerability is due to incorrect handling of malformed H.323 packets. An attacker could exploit this vulnerability by sending a crafted H.323 packet through the affected device. An exploit could allow the attacker to reload the Cisco ASA 1000V Cloud Firewall, resulting in denial of service (DoS) condition.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Cisco ASA Software for the Cisco ASA 1000v Cloud Firewall versions 8.7.1 and 22.214.171.124 are vulnerable.
To exploit the vulnerability, the attacker must send malicious packets to the targeted system, likely requiring the attacker to access trusted, internal networks. This access requirement limits the likelihood of a successful exploit.
Although H.323 inspection uses UDP ports 1718 and 1719 and TCP port 1720, ports dynamically negotiated by H.323 call signaling setup may be used as attack vectors to trigger 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 targeted device to reload, resulting in a DoS condition. Repeated attacks could result in a sustained DoS condition.
The vulnerability is due to incorrect handling of malformed H.323 IPv4 packets processed by the affected software when H.323 inspection for H.225 messages is enabled.
An unauthenticated, remote attacker could exploit this vulnerability by sending malformed H.323 packets via UDP ports 1718 and 1719 or TCP port 1720 through the affected device. A successful exploit could allow the attacker to reload the device, resulting in DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling H.323 inspection for H.225 messages if H.323 inspection is not required by issuing the following command: no inspect h323 h225
Administrators are advised to allow only trusted users to have network access.
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 critical 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.
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
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