Cisco AsyncOS Software for Cisco Email Security Appliance and Cisco Content Security Management Appliance contains a vulnerability that could allow an authenticated, remote attacker to execute arbitrary code. Updates are available.
A vulnerability in the End User Safelist/Blocklist (SLBL)
function of Cisco AsyncOS Software for Cisco Email Security Appliance and Cisco Content Security Management Appliance could allow an authenticated, remote attacker to execute arbitrary code on an affected system.
vulnerability is due to insufficient validation of the SLBL database file.
An attacker could exploit this vulnerability by substituting a valid
SLBL database file with a tampered file. The tampered file could contain
shell code that would be executed by the affected system when a specific
event is triggered (for example, when a new email is received that
triggers the SLBL check). To exploit this vulnerability, the attacker must have the FTP and SLBL services enabled, at least temporarily, and have valid credentials to upload the tampered
SLBL database file via FTP.
An exploit could allow the attacker to execute
arbitrary code on the affected system with the privileges of the root
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Cisco AsyncOS Software running on the following Cisco products are affected:
Cisco Email Security Appliance versions prior to 8.0.1-023
Cisco Content Security Management Appliance versions prior to 8.1.1-013
To exploit this vulnerability, an attacker must authenticate to a targeted device. This access requirement reduces the likelihood 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 authenticated, remote attacker could exploit this vulnerability to execute arbitrary code with root-level privileges. A successful exploit could result in a complete system compromise.
The vulnerability is due to insufficient validation of the SLBL database file by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by substituting a valid SLBL database file with a malicious SLBL file containing shell code. After the affected system triggers a specific event, the attacker could execute the shell code from the malicious SLBL file with the privileges of the root user, which could result in a complete system compromise.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Once a valid SLBL file has been loaded on a system, administrators may consider disabling the FTP and SLBL services to reduce the exposure of this vulnerability by preventing the replacement of the valid SLBL file with a malicious SLBL file.
Administrators are advised to monitor critical 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 email at firstname.lastname@example.org.
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