A vulnerability in the Graphical User Interface (GUI) function in the web framework code could allow an unauthenticated,
remote attacker to cause multiple processes to become unresponsive, resulting in a denial of service condition.
The vulnerability is due to
improper handling, processing and termination of HTTP and HTTPS connections. An attacker could exploit this vulnerability by
sending multiple HTTP or HTTPS requests to any management enabled interfaces of
the affected system. A full TCP three-way handshake is required to
exploit this vulnerability. An exploit could allow the attacker prevent management access via the GUI and cause other critical process 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.
Indicators of Compromise
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 Web Security Appliance (WSA) prior to 7.1.3-013, 7.1.4-101, 7.5.0-838, 7.5.1-201, and 7.7.0-602
Cisco Content Security Management Appliance (SMA) prior to 7.9.1-102 and 8.0.0-404
The vulnerability is due to improper handling, processing, and termination of HTTP and HTTPS connections by the affected device.
An attacker could exploit this vulnerability by sending multiple HTTP or HTTPS requests to any management-enabled interfaces of the affected system. If successful, the attacker could prevent management access via the GUI and cause other critical processes to become unresponsive, resulting in a DoS condition.
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send multiple HTTP or HTTPS requests to any management-enabled interfaces of 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.
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling management access to the GUI or restricting IP addresses that can access the management interface as mitigation strategies. Details about these actions are in the security advisories listed in the "Vendor Announcements" section of this alert.
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 email at email@example.com.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.