Cisco ACE Log Retention Denial of Service Vulnerability

A vulnerability in the SSL logging daemon of Cisco Application Control Engine (ACE) could allow an unauthenticated, remote attacker to cause a denial of service condition on the affected device.

The vulnerability occurs because the Cisco ACE fails to rotate logs from SSL sessions, exhausting the hard drive of free space. An attacker could exploit this vulnerability by sending excessive amounts of SSL connections to the affected device. An exploit could allow the attacker to exhaust remaining free space on the hard drive, causing operations such as configuration and writing configurations on the disk to fail. Additional errors can be observed on the Cisco ACE console.

Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.

To exploit this vulnerability, an attacker may require access to a trusted, internal network to send a series of SSL connections to the targeted system. This access requirement could limit the likelihood of a successful exploit.

Customers are advised to review the bug reports in the “Vendor Announcements” section for a current list of affected versions.

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.