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statd Format Bug Vulnerability on NSM

  [JSA10440] Show Article Properties


Legacy Advisory Id:
PSN-2010-05-762
Product Affected:
This is a "zero day" vulnerability present on all NSM products from the initial software version up to but not including the first fixed releases mentioned previously in this document.
Problem:
The daemon process called "rpc.statd" provides file status information via Remote Procedure Call (RPC) services on NSM products. rpc.statd on affected systems contains a format string vulnerability when calling the syslog() function. A malicious user can exploit this vulnerability to inject executable code into the process address space which will overwrite the return address of the function and force the program to execute additional inserted code. rpc.statd requires root privileges to open network socket when the process is started, but it fails to properly drop those privileges later. Therefore, code injected by the malicious user will execute with root privileges, possibly leading to a complete compromise of a vulnerable system.

This issue affects NSMXpress, NSM Appliance, and NSM3000 if running an affected release of NSM software. NSM Server does not include the vulnerable service in its software distribution. NSM Server installations may or may not be vulnerable depending on what version of the affected service is present and available on the underlying platform as provided independently by the customer.

This issue is being tracked as PR 465295. While this PR is not viewable by customers, it can be used as a reference when discussing the issue with JTAC.
Solution:
To address this issue, rpc.statd has been disabled in the fixed releases listed below.

All software releases built on or after 2010-02-23 contain the fix for this specific issue. Those releases include NSMXpress release 5.145238, release 2010.1, and all subsequent releases. Upgrading NSMXpress, NSM Appliance, and NSM3000 to a fixed release will resolve the vulnerability.

Please note that the affected services are not included in NSM Server software, and the vulnerability, if present, will not be removed by upgrading to an unaffected version of NSM Server software. The issue can be addressed by upgrading the underlying operating system on the hosting server or, if an upgrade is not possible, then workarounds should be considered and applied.

Workaround:

Disable the rpc.statd service

The threat can be eliminated by disabling rpc.statd on affected NSM systems and then rebooting, as follows:

# chkconfig rpc.statd off
# reboot
Implementation:
Customers are encouraged to upgrade affected systems to fixed versions of software. KB16765 - "In which releases are vulnerabilities fixed?" describes which releases are selected to receive fixes for vulnerabilities per Juniper Networks' "End of Engineering" and "End of Life" support policies.

If upgrading software is not likely to occur for some time, then a workaround should be employed. In all cases, customers should evaluate the risks and benefits of any given workaround to ensure that it is appropriate and practical in the customer's own production environment.

How to obtain fixed software:
NSM Maintenance Releases are available at http://support.juniper.net from the "Download Software" links.

If a Maintenance Release is not adequate and access to NSM patches is needed, open a customer support case. A JTAC engineer will review your request and respond, ensuring that you will be provided with the most appropriate Patch Release for your specific situation.
Related Links:
CVSS Score:
10.0 (AV:N/AC:L/Au:N/C:C/I:C/A:C/E:F/RL:W/RC:C)
Severity Level:
Critical
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories".