Multiple Cisco products contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the IronPort Spam Quarantine (ISQ) function in the web framework code could allow an unauthenticated,
remote attacker to cause multiple critical processes to become unresponsive, resulting in a denial of service condition.
The vulnerability is due to
improper handling and processing of TCP connection requests
sent at high rate. An attacker could exploit this vulnerability by
a sending sequence of TCP requests to the ISQ service port that is open on the ISQ-enabled interfaces of
the affected system. A full TCP three-way handshake is required to
exploit this vulnerability. An successful exploit could allow the attacker to crash
or make unresponsive the ISQ service and cause other critical processes to become unresponsive, resulting in a denial of service condition. A hard reboot of the affected system is needed to restore full functionality.
Cisco has confirmed the vulnerability in multiple security advisories and has released software updates.
The following Cisco products are vulnerable:
Cisco Email Security Appliance (ESA) prior to 7.1.5-106 and prior to 7.6.3-019
Cisco Content Security Management Appliance (SMA) prior to 7.9.1-102 and prior to 8.0.0-404
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send a sequence of TCP requests to the affected system while establishing a full TCP three-way handshake. This access requirement limits 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 several critical processes on the targeted system to become unresponsive, resulting in a denial of service (DoS) condition.
The vulnerability is due to improper handling and processing of TCP connection requests sent at high rate to the affected system. The vulnerability could be triggered by IPv4 or IPv6 traffic directed to the ISQ-enabled interfaces of an affected system via TCP port 82 or TCP port 83.
An unauthenticated, remote attacker could exploit this vulnerability by a sending sequence of TCP requests to the ISQ service port that is open on the ISQ-enabled interfaces of the affected system. An successful exploit could allow the attacker to crash or make unresponsive the ISQ service and cause other critical processes to become unresponsive, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling end-user access to the ISQ service on affected devices. Details about these actions are in the security advisories listed in the "Vendor Announcements" section of this alert.
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 email@example.com.
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