Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2020.3832
Cisco Email Security Appliance Zip Content Filter Bypass Vulnerability
5 November 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Email Security Appliance
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Reduced Security -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-26082
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-zip-bypass-gbU4gtTg
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco Email Security Appliance Zip Content Filter Bypass Vulnerability
Priority: Medium
Advisory ID: cisco-sa-esa-zip-bypass-gbU4gtTg
First Published: 2020 November 4 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvv38679
CVE-2020-26082
CWE-20
Summary
o A vulnerability in the zip decompression engine of Cisco AsyncOS Software
for Cisco Email Security Appliance (ESA) could allow an unauthenticated,
remote attacker to bypass content filters that are configured on an
affected device.
The vulnerability is due to improper handling of password-protected zip
files. An attacker could exploit this vulnerability by sending a malicious
file inside a crafted zip-compressed file to an affected device. A
successful exploit could allow the attacker to bypass configured content
filters that would normally drop the email.
Cisco has released software updates that address this vulnerability. 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-esa-zip-bypass-gbU4gtTg
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco ESA releases
earlier than Release 13.5.2.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Workarounds
o There are no workarounds that address this vulnerability.
Fixed Software
o When considering software upgrades , customers are advised to regularly
consult the advisories for Cisco products, which are available from the
Cisco Security Advisories 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.
Fixed Releases
At the time of publication, Cisco ESA releases 13.5.2 and later contained
the fix for this vulnerability.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Exploitation and Public Announcements
o 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
o This vulnerability was found during the resolution of a Cisco TAC support
case.
Cisco Security Vulnerability Policy
o 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.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-esa-zip-bypass-gbU4gtTg
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-NOV-04 |
+----------+---------------------------+----------+--------+--------------+
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=i3w1
-----END PGP SIGNATURE-----