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AUSCERT External Security Bulletin Redistribution
ESB-2019.2442
Cisco Email Security Appliance Content Filter Bypass Vulnerabilities
4 July 2019
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Email Security Appliance
Publisher: Cisco Systems
Operating System: Network Appliance
Impact/Access: Reduced Security -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2019-1933 CVE-2019-1921
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-esa-bypass
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-esa-filterpass
Comment: This bulletin contains two (2) security advisories.
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco Email Security Appliance Content Filter Bypass Vulnerability
Priority: Medium
Advisory ID: cisco-sa-20190703-esa-bypass
First Published: 2019 July 3 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvp88949
CVE-2019-1921
CWE-20
CVSS Score:
5.8 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X
Summary
o A vulnerability in the attachment scanning of Cisco AsyncOS Software for
Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote
attacker to bypass configured content filters on the device.
The vulnerability is due to improper input validation of the email body. An
attacker could exploit this vulnerability by naming a malicious attachment
with a specific pattern. A successful exploit could allow the attacker to
bypass configured content filters that would normally block the attachment.
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-20190703-esa-bypass
Affected Products
o The information provided in this advisory is the best available information
as of the time of publication. Please consult the Release Note Enclosure on
any associated bug ID for the most complete, accurate, and up-to-date
information.
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 additional information is needed, customers are advised to contact the
Cisco Technical Assistance Center (TAC) or their contracted maintenance
providers.
Vulnerable Products
This vulnerability affects Cisco Email Security Appliance.
For information about affected software releases, consult the Cisco bug IDs
at the top of this advisory.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Fixed Releases
For information about fixed software releases, consult the Cisco bug ID(s)
at the top of this advisory.
Workarounds
o There are no workarounds that address this vulnerability.
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-20190703-esa-bypass
Revision History
o +---------+---------------------------+---------+--------+---------------+
| Version | Description | Section | Status | Date |
+---------+---------------------------+---------+--------+---------------+
| 1.0 | Initial public release. | - | Final | 2019-July-03 |
+---------+---------------------------+---------+--------+---------------+
- --------------------------------------------------------------------------------
Cisco Email Security Appliance Content Filter Bypass Vulnerability
Priority: Medium
Advisory ID: cisco-sa-20190703-esa-filterpass
First Published: 2019 July 3 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvo55451
CVE-2019-1933
CWE-20
CVSS Score:
5.8 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X
Summary
o A vulnerability in the email message scanning of Cisco AsyncOS Software for
Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote
attacker to bypass configured filters on the device.
The vulnerability is due to improper input validation of certain email
fields. An attacker could exploit this vulnerability by sending a crafted
email message to a recipient protected by the ESA. A successful exploit
could allow the attacker to bypass configured message filters and inject
arbitrary scripting code inside the email body. The malicious code is not
executed by default unless the recipient's email client is configured to
execute scripts contained in emails.
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-20190703-esa-filterpass
Affected Products
o The information provided in this advisory is the best available information
as of the time of publication. Please consult the Release Note Enclosure on
any associated bug ID for the most complete, accurate, and up-to-date
information.
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 additional information is needed, customers are advised to contact the
Cisco Technical Assistance Center (TAC) or their contracted maintenance
providers.
Vulnerable Products
This vulnerability affects Cisco Email Security Appliance.
For information about affected software releases, consult the Cisco bug ID
(s) at the top of this advisory.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Fixed Releases
For information about fixed software releases, consult the Cisco bug ID(s)
at the top of this advisory.
Workarounds
o There are no workarounds that address this vulnerability.
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-20190703-esa-filterpass
Revision History
o +---------+---------------------------+---------+--------+---------------+
| Version | Description | Section | Status | Date |
+---------+---------------------------+---------+--------+---------------+
| 1.0 | Initial public release. | - | Final | 2019-July-03 |
+---------+---------------------------+---------+--------+---------------+
- --------------------------END INCLUDED TEXT--------------------
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