Advisory ID: cisco-sa-19990819-dbaccess
For Public Release 1999 August 19 15:00 UTC (GMT)
In CiscoSecure Access Control Server (CiscoSecure ACS) for UNIX,
versions 1.0 through 2.3.2, there is a database access protocol that could
permit unauthorized remote users to read and write the server database without
authentication. Depending on the network environment, this might permit
unauthorized users to modify the access policies enforced by the CiscoSecure
ACS. A utility that is capable of using this protocol to read or modify a
database is shipped with the CiscoSecure ACS product.
This vulnerability can be eliminated by either a CiscoSecure
configuration change, or network configuration change. Cisco has provided a new
release that changed a default setting, in order to ensure higher default
This vulnerability has Cisco bug ID CSCdm71489.
This advisory is posted at
This section provides details on affected products.
If you are running an affected version of CiscoSecure ACS for UNIX, and
if you have not modified the configuration to strictly permit connections from
trusted hosts, and if untrusted users can make TCP connections to TCP port 9900
on the computer on which you have installed CiscoSecure ACS, then you are
Users of CiscoSecure ACS for Windows NT are not
No other Cisco products are currently known to be affected by these
This vulnerability has been assigned Cisco bug ID CSCdm71489.
Cisco has provided scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0.
CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response.
Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks.
Cisco has provided an FAQ to answer additional questions regarding CVSS at
Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at
The impact may vary, depending whether potential attackers have access
to port 9900 on the CiscoSecure ACS computer. This vulnerability could allow an
attacker to remove accounts, add accounts and change passwords or privileges in
the user database, including implementing an administrative account, that would
give them control of the CiscoSecure ACS server.
Customers who may have been vulnerable to attack are advised to review
privileged accounts, and any suspicious database changes.
This applies ONLY to CiscoSecure ACS for UNIX, and is present in all
versions, up to version 2.3.2. Version 2.3.3 of CiscoSecure ACS for UNIX has
been modified to validate administrative clients by default.
This vulnerability applies only to the software product CiscoSecure
Access Control Server for UNIX, and does not apply to CiscoSecure Access
Control Server for NT.
Two workarounds for this vulnerability exist.
One workaround consists of enabling client validation within
CiscoSecure ACS for UNIX. A caveat to this workaround is that there are some
versions of CiscoSecure ACS for UNIX that are subject to another defect, which
prevents access to additional administration utilities (the Advanced
Administration GUI) within CiscoSecure ACS for UNIX when the client validation
feature is enabled. This problem is identified in CSCdm72555 which affects
versions 2.3.1 and 2.3.2, and CSCdk55423, which affects versions 2.2.2, 2.2.3
of CiscoSecure ACS for UNIX. This workaround will not be effective in
CiscoSecure ACS for UNIX version 2.2.2, 2.2.3, 2.3.1 and 2.3.2, and customers
are encouraged to upgrade to a version that does not include this defect.
Version 2.3.3 is currently available and is not susceptible to the above
You must edit the CSCconfig.ini file, list the permitted remote access
hosts, enable remote client validation. TACACS or RADIUS clients do NOT need to
be listed under this setting, only hosts that are permitted to administer the
server should be listed.
In the following example, 'acs_srv_machine' resolves to localhost, and
we are providing remote administration privileges to the hosts 'client_machine'
and the ip address 172.16.23.23. Permitted clients may be defined by a
hostname, or an ip address.
CSCconfig.ini file should be edited with the following information:
;if ValidateClients=true, than we only allow the clients with ids listed
; to connect to the dbserver
100 = acs_srv_machine
100 = client_machine
100 = 172.16.23.23
ValidateClients = true
An additional configuration parameter "FastAdminValidClients" was
added in CiscoSecure ACS version 2.3.3 allowing the Fast Administrator Web
based GUI to permit the same IP addresses specified in the valid clients list,
to further restrict client access.
A second workaround is to use filtering on other network devices, such
as a firewall, to control or block access to TCP port 9900 on the CiscoSecure
ACS for UNIX server.
Cisco has made free software available to address this vulnerability
for affected customers. Prior to deploying software, customers should consult
their maintenance provider or check the software for feature set compatibility
and known issues specific to their environment.
Customers may only install and expect support for the feature sets they
have purchased. By installing, downloading, accessing or otherwise using such
software upgrades, customers agree to be bound by the terms of Cisco's software
license terms found at
or as otherwise set forth at Cisco.com Downloads at
Do not contact either "email@example.com" or "firstname.lastname@example.org"
for software upgrades.
Customers with contracts should obtain upgraded software through their
regular update channels. For most customers, this means that upgrades should be
obtained through the Software Center on Cisco's worldwide website at
Customers whose Cisco products are provided or maintained through prior
or existing agreement with third-party support organizations such as Cisco
Partners, authorized resellers, or service providers should contact that
support organization for guidance and assistance with the appropriate course of
action in regards to this advisory.
The effectiveness of any workaround or fix is dependent on specific
customer situations such as product mix, network topology, traffic behavior,
and organizational mission. Due to the variety of affected products and
releases, customers should consult with their service provider or support
organization to ensure any applied workaround or fix is the most appropriate
for use in the intended network before it is deployed.
Customers who purchase direct from Cisco but who do not hold a Cisco
service contract and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain software patches and bug fixes by contacting the Cisco Technical Assistance Center (TAC). TAC
contacts are as follows.
+1 800 553 2447 (toll free from within North America)
+1 408 526 7209 (toll call from anywhere in the world)
Have your product serial number available and provide the URL of this notice as evidence of entitlement to a software patch or bug fix. Customers without service contracts should request a software patch or bug fix through the TAC.
for additional TAC contact information, including special localized telephone
numbers and instructions and e-mail addresses for use in various
Cisco does not have any reports of malicious use of this vulnerability.
CiscoSecure ACS for UNIX Reference Guide does include a cautionary note
regarding this vulnerability.
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 stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors.
This notice will be posted on Cisco's Worldwide Web site at
In addition to Worldwide Web posting, the initial version of this notice is
being sent to the following e-mail and Usenet news recipients:
email@example.com (includes CERT/CC)
Various internal Cisco mailing lists
Future updates of this notice, if any, will be placed on Cisco's
Worldwide Web server, but may or may not be actively announced on mailing lists
or newsgroups. Users concerned about this problem are encouraged to check the
URL given above for any updates.
Initial public release.