Advisory ID: cisco-sa-20020702-acsunix-acmeweb
For Public Release 2002 July 2 18:00 UTC (GMT)
Cisco Secure Access Control Server for Unix implements the Acme.server
and is therefore vulnerable to a directory traversal vulnerability. The fix has
been included in ACS Unix version 220.127.116.11 which is currently available.
This vulnerability is detailed in Cisco Bug ID CSCdu47965.
This advisory is available at:
This section provides details on affected products.
The defects described in this document are present in releases
beginning with version 2.0 up to and including version 2.3.6 of Cisco Secure
ACS for Unix Server.
Cisco Secure ACS for Windows NT is not vulnerable
to this issue. Cisco Access Registrar is not vulnerable to
No other Cisco products are currently known to be affected by these
This vulnerability exists within the Acme.server program that is part
of the Cisco Secure ACS Unix installation. This vulnerability has been repaired
in the Acme.server utility. The patch is available for Cisco customers, and has
now been incorporated into the Cisco Secure ACS Unix product.
The vulnerability is triggered when someone browses to the server URL
and adds trailing slashes as in the following example:
http://servername:9090///. This exploit will display the files and filesystem
of the target server.
This vulnerability has been assigned Cisco bug ID CSCdu47965.
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 9090 on the Cisco Secure ACS computer. This vulnerability could allow
an attacker to view files and directory structures on the target system. Access
to the encrypted password file provided by this vulnerability, for example,
would allow an attacker access through a successful dictionary attack against
the listed accounts.
Customers who may have been vulnerable to attack are advised to review
privileged accounts and any suspicious database changes, and to change
There is a patch available, and the fixes are included in Cisco Secure
ACS Unix version 18.104.22.168 and all versions going forward. For existing versions,
the patch may be applied, which resolves the issue. There is no need to upgrade
to a newer version.
Workarounds for this vulnerability include general recommendations of
protecting the Cisco Secure ACS for Unix with strong firewalls, access
controls, and preventing any external or unauthenticated access to the system,
and to port 9090 in particular. This is an interim workaround only, and a patch
or upgrade is recommended.
For this issue, a patch is available which may be installed in place of
an upgrade. The patch is available at the following temporary location:
For any assistance with the patch, please contact the TAC. This patch
fixes the security problem with the Acme.server. It includes the modified files
provided by Acme. This patch can be applied for any supported version of Cisco
Secure, that is, CiscoSecure/Unix 2.3(3) or later. The patch consists of one
To install the patch, follow the instructions below. The commands need
to be executed on your Cisco Secure ACS Unix by the administrator.
Stop Cisco Secure by entering the command:
Change to the base directory where Cisco Secure is installed.
Copy the compressed tar file Acme-Patch.tar.Z into the current
Uncompress and untar the file.
tar xvf Acme-Patch.tar
Start Cisco Secure with the command:
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 "firstname.lastname@example.org" or "email@example.com"
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
The issue with the Acme.server was posted to the Bugtraq list June 2001
although no specific mention of the Cisco product was made in the original
posting. Cisco PSIRT is not aware of any malicious use of the vulnerability
described in this advisory.
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 the Cisco worldwide website at
In addition to worldwide web posting, a text version of this notice is
clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail
and Usenet news recipients:
firstname.lastname@example.org (includes CERT/CC)
Various internal Cisco mailing lists
Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on mailing lists or
newsgroups. Users concerned about this problem are encouraged to check the
above URL for any updates.
Update to Affected Products section
Update to Workarounds section
Initial Public Release