Cisco Security Advisory-
Multiple vulnerabilities exist in the Cisco Virtual Private Network (VPN) 5000 Client software. These vulnerabilities are documented as Cisco bug ID CSCdx17109 and CSCdy20065. There are some workarounds available to mitigate the effects of these vulnerabilities.
This advisory will be posted at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20020918-vpn5k-vulnerability.
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This section provides details on affected products.
Vulnerable Products
DDTS - Description
Affected Releases
CSCdx17109 - MAC OS VPN 5000 Client password vulnerability
MAC OS VPN 5000 Client releases earlier than 5.2.2
CSCdy20065 - Linux and Solaris VPN 5000 Client buffer overflow vulnerability
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Linux VPN 5000 Client releases earlier than 5.2.7
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Solaris VPN 5000 Client releases earlier than
5.2.8
Products Confirmed Not Vulnerable
The Cisco VPN 3000 client and the Cisco VPN client are not affected.
No other Cisco products are currently known to be affected by these vulnerabilities.
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Linux VPN 5000 Client releases earlier than 5.2.7
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The VPN Client software program on a remote workstation, communicating with a Cisco VPN device on an enterprise network or with a service provider, creates a secure connection over the Internet. Through this connection you can access a private network as if you were an onsite user.
DDTS - Description
Details
CSCdx17109 - MAC OS VPN 5000 Client password vulnerability
When saving the "Default Connection" in the resource fork of the preferences file, the client saves the entire contents of the data structure that represents the "Default Connection" which includes the most recently used login password.
This password can be read in plain text using the ResEdit tool. This occurs regardless of whether "SaveSecrets" is enabled or disabled, and regardless of whether you encrypt passwords or not.
CSCdy20065 - Linux and Solaris VPN 5000 Client buffer overflow vulnerability
Two buffer overflow issues exist in the VPN 5000 Client for Linux and Solaris. One in the close_tunnel binary and one in the open_tunnel binary. To exploit the vulnerability one has to be logged in on the workstation. The buffer overflows could be locally exploited to gain root privileges on the workstation.
These vulnerabilities are documented in the Cisco Bug Toolkit as Bug IDs CSCdx17109 and CSCdy20065, and can be viewed after September 19, 2002 at 1500 UTC. To access this tool, you must be a registered user and you must be logged in.
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Workarounds are described in this table.
DDTS - Description
Workaround / Mitigation Techniques
CSCdx17109 - MAC OS VPN 5000 Client password vulnerability
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An attempt to log in using a wrong password after one has
finished using the connection causes the wrong password to be stored in the
resources fork.
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Turn the "Save Secrets" option off on the concentrator. This
will stop the VPN 5000 Client from saving the password.
CSCdy20065 - Linux and Solaris VPN 5000 Client buffer overflow vulnerability
There is no workaround.
The Cisco PSIRT recommends that affected users upgrade to a fixed software version of code.
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An attempt to log in using a wrong password after one has
finished using the connection causes the wrong password to be stored in the
resources fork.
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When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.
In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center ("TAC") or your contracted maintenance provider for assistance.
DDTS - Description
Affected Releases
CSCdx17109 - MAC OS VPN 5000 Client password vulnerability
MAC OS VPN 5000 Client release 5.2.2 or later
CSCdy20065 - Linux and Solaris VPN 5000 Client buffer overflow vulnerability
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Linux VPN 5000 Client release 5.2.7 or later
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Solaris VPN 5000 Client release 5.2.8 or later
The procedure to upgrade to the fixed software version is detailed at http://www.cisco.com/univercd/cc/td/doc/product/aggr/vpn5000/client/.
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Linux VPN 5000 Client release 5.2.7 or later
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The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory.
Cisco Bug ID CSCdx17109 was reported to Cisco by a customer. Cisco Bug ID CSCdy20065 was reported to Cisco by Niels Heinen of Ubizen.
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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.
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