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AUSCERT External Security Bulletin Redistribution
ESB-2020.3036
Cisco Email Security Appliance Vulnerabilities
4 September 2020
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Email Security Appliance
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Access Confidential Data -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-3548 CVE-2020-3546
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-tls-dos-xW53TBhb
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-info-disclosure-vMJMMgJ
Comment: This bulletin contains two (2) Cisco Systems security advisories.
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco Email Security Appliance Denial of Service Vulnerability
Priority: Medium
Advisory ID: cisco-sa-esa-tls-dos-xW53TBhb
First Published: 2020 September 2 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs: CSCvu35999
CVE-2020-3548
CWE-407
Summary
o A vulnerability in the Transport Layer Security (TLS) protocol
implementation of Cisco AsyncOS software for Cisco Email Security Appliance
(ESA) could allow an unauthenticated, remote attacker to cause high CPU
usage on an affected device, resulting in a denial of service (DoS)
condition.
The vulnerability is due to inefficient processing of incoming TLS traffic.
An attacker could exploit this vulnerability by sending a series of crafted
TLS packets to an affected device. A successful exploit could allow the
attacker to trigger a prolonged state of high CPU utilization. The affected
device would still be operative, but response time and overall performance
may be degraded.
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-tls-dos-xW53TBhb
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco ESA software
releases 13.5.1-277 and earlier.
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
For information about fixed software releases, see the Details section in
the bug ID(s) at the top of this advisory.
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 internal security testing.
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-tls-dos-xW53TBhb
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-SEP-02 |
+----------+---------------------------+----------+--------+--------------+
- --------------------------------------------------------------------------------
Cisco Email Security Appliance Information Disclosure Vulnerability
Priority: Medium
Advisory ID: cisco-sa-esa-info-disclosure-vMJMMgJ
First Published: 2020 September 2 16:00 GMT
Version 1.0: Final
Workarounds: Yes
Cisco Bug IDs: CSCvp01770
CVE-2020-3546
CWE-20
CVSS Score:
5.3 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:X/RL:X/RC:X
Summary
o A vulnerability in the web-based management interface of Cisco AsyncOS
software for Cisco Email Security Appliance (ESA) could allow an
unauthenticated, remote attacker to access sensitive information on an
affected device.
The vulnerability is due to insufficient validation of requests that are
sent to the web-based management interface. An attacker could exploit this
vulnerability by sending a crafted request to the interface of an affected
device. A successful exploit could allow the attacker to obtain the IP
addresses that are configured on the internal interfaces of the affected
device.
There is a workaround that addresses this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-esa-info-disclosure-vMJMMgJ
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco ESA software
releases 13.5.1 and earlier.
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 is a workaround that addresses this vulnerability.
In setups that do not involve Network Address Translation (NAT), enabling
the Host header protection feature would prevent exploitation of this
vulnerability. The following example shows how to use the adminaccessconfig
command, followed by the HOSTHEADER operation, to enable the Host header
protection feature:
mail.example.com> adminaccessconfig
Choose the operation you want to perform:
- BANNER - Configure login message (banner) for appliance administrator login.
- WELCOME - Configure welcome message (post login message) for appliance administrator login.
- IPACCESS - Configure IP-based access for appliance administrative interface.
- CSRF - Configure web UI Cross-Site Request Forgeries protection.
- XSS - Configure Cross-Site Scripting Attack protection.
- HOSTHEADER - Configure option to use host header in HTTP requests.
- TIMEOUT - Configure GUI and CLI session inactivity timeout.
- MAXHTTPHEADERFIELDSIZE - Configure maximum HTTP header Field size.
- HOW-TOS - Configure How-Tos feature.
[]> HOSTHEADER
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
For information about fixed software releases, see the Details section in
the bug ID(s) at the top of this advisory.
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-info-disclosure-vMJMMgJ
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-SEP-02 |
+----------+---------------------------+----------+--------+--------------+
- --------------------------END INCLUDED TEXT--------------------
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