ESB-2017.2930 - [Cisco] Cisco Web Security Appliance (WSA): Unauthorised access - Remote/unauthenticated 2017-11-16

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.2930
            Cisco Web Security Appliance: File Filtering Bypass
                             16 November 2017

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Cisco Web Security Appliance (WSA)
Publisher:         Cisco Systems
Operating System:  Cisco
Impact/Access:     Unauthorised Access -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-12303  

Original Bulletin: 
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171115-wsa

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Cisco Web Security Appliance Advanced Malware Protection File Bypass
Vulnerability

Severity: Medium
Advisory ID: cisco-sa-20171115-wsa
First Published: 2017 November 15 16:00  GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs: CSCvf52943 CVE-2017-12303 CWE-358
CVSS Score: Base 5.3
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:X/RL:X/RC:X

CVE-2017-12303
CWE-358

Summary

  * A vulnerability in the Advanced Malware Protection (AMP) file filtering
    feature of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA)
    could allow an unauthenticated, remote attacker to bypass a configured AMP
    file filtering rule. The file types affected are zipped or archived file
    types.

    The vulnerability is due to incorrect and different file hash values when
    AMP scans the file. An attacker could exploit this vulnerability by sending
    a crafted email file attachment through the targeted device. An exploit
    could allow the attacker to bypass a configured AMP file filter.

    There are no workarounds that address this vulnerability.

    This advisory is available at the following link:
    https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-20171115-wsa

Affected Products

  * Vulnerable Products

    This vulnerability affects Cisco Web Security Appliance. For information
    about affected software releases, consult the Cisco bug ID(s) at the top of
    this advisory.

    Products Confirmed Not Vulnerable

    No other Cisco products are currently known to be affected by this
    vulnerability.

Workarounds

  * There are no workarounds that address this vulnerability.

Fixed Software

  * For information about fixed software releases, consult the Cisco bug ID(s)
    at the top of this advisory.

    When considering software upgrades, customers are advised to regularly
    consult the advisories for Cisco products, which are available from the
    Cisco Security Advisories and Alerts page, to determine exposure and a
    complete upgrade solution.

    In all cases, customers should ensure that the devices to be upgraded
    contain sufficient memory and confirm that current hardware and software
    configurations will continue to be supported properly by the new release.
    If the information is not clear, customers are advised to contact the Cisco
    Technical Assistance Center (TAC) or their contracted maintenance
    providers.

Exploitation and Public Announcements

  * 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.

Source

  * This vulnerability was found during the resolution of a Cisco TAC support
    case.

Cisco Security Vulnerability Policy

  * 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.

Subscribe to Cisco Security Notifications

  * Subscribe

URL

  * https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-20171115-wsa

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Legal Disclaimer

  * THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND
    OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR
    FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT
    OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES
    THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

    A standalone copy or paraphrase of the text of this document that omits the
    distribution URL is an uncontrolled copy and may lack important information
    or contain factual errors. The information in this document is intended for
    end users of Cisco products.

Cisco Security Vulnerability Policy

  * 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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