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AUSCERT External Security Bulletin Redistribution
Secure Shell Denial of Service Vulnerability
16 April 2013
AusCERT Security Bulletin Summary
Product: Cisco Adaptive Security Appliance (ASA) Software
Cisco Firewall Services Module (FWSM)
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
CVE Names: CVE-2013-1193
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Secure Shell Denial of Service Vulnerability
CVE ID: CVE-2013-1193
Release Date: 2013 April 12 10:39 UTC (GMT)
Last Updated: 2013 April 12 10:39 UTC (GMT)
A vulnerability in the implementation of the Secure Shell (SSH)
function could allow an unauthenticated, remote attacker to deny SSH
management access to legitimate users.
The vulnerability is due to improper implementation of the logic to terminate
SSH sessions. An attacker could exploit this vulnerability by starting an SSH
session to the affected system. This vulnerability affects both SSHv1 and v2.
An exploit could allow the attacker to deny SSH management access to
legitimate users. The attacker can deny the access for 60 seconds, and then
the affected system will release the resource and users will be able to use
the SSH service again. However, repeated exploitation may lead to a denial of
Product More Information CVSS
Cisco Adaptive Security Appliance
(ASA) Software CSCue63881, CSCuf51892 5.0/4.1
Cisco Firewall Services Module (FWSM) CSCue78671, CSCug26937 5.0/4.5
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