AV:N/AC:M/Au:N/C:N/I:N/A:P/E:F/RL:U/RC:C
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A vulnerability in the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to generate malformed Domain-Based Message Authentication, Reporting, and Conformance (DMARC) policy records to the targeted system.
The vulnerability occurs because the affected ESA is not able to receive email messages from domains with malformed DMARC policy records. An attacker could exploit this vulnerability by enabling DMARC or modifying system contents. A successful exploit could result in a denial of service (DoS) condition.
Cisco has confirmed the vulnerability; however, software updates are not available.
To exploit this vulnerability, an attacker must enable DMARC or modify other system contents on the targeted device. In a typical network environment, the targeted device may be located on trusted, internal networks behind firewall restrictions, making exploitation more difficult from attackers on untrusted networks.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
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Cisco has released bug ID CSCuv14806 for registered users, which contains additional details and an up-to-date list of affected product versions.
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Administrators are advised to contact the vendor regarding future updates and releases.
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 affected systems.
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Software updates are not available.
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The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Version Description Section Status Date 1.0 Initial Release NA Final 2015-Jul-15
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