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Simultaneous multithreading processors may leak information through cache eviction analysis techniques

Vulnerability Note VU#911878

Original Release Date: 2005-05-23 | Last Revised: 2005-08-05

Overview

Operating systems on hardware platforms supporting simultaneous multi-threading (Hyper-Threading technology in particular) are potentially vulnerable to information leakage to local users. Proof of concept papers and code demonstrating successful attacks against cryptographic keys are in public circulation.

Description

Hyper-Threading (HT) Technology allows two series of instructions to run simultaneously and independently on a single processor. With Hyper-Threading Technology enabled, the system treats a physical processor as two "logical" processors. Each logical processor is allocated a thread on which to work, as well as a share of execution resources such as cache memories, execution units, and buses.

Information could potentially be deduced by local users using programs capable of shared memory cache eviction analysis. Proof of concept code using timing and cache eviction analysis techniques have demonstrated that cyptographic keys can be deduced on Intel processors with Hyper-Threading technology (HTT) . It is likely that similar techniques could be employed on other processor architectures that support simultaneous multithreading.

This vulnerability is applicable to many operating system platforms running on a hardware platform that supports simultaneous multithreading (Intel HTT in particular).

Colin Percival has released a paper "Cache Missing for Fun and Profit" that demonstrates shared access to memory caches provide a potential covert channel between threads, and also permit a malicious thread to monitor the execution of another thread, potentially allowing for theft of cryptographic keys.

Vendors have started providing patches and configuration information to disable simultaneous multithreading/HTT support.

Warning: On dual-core (multiple CPU) systems this could have the undesirable effect of disabling all but one of the CPUs. For single core (CPU) systems this workaround may still impact the performance of the server (depending on load).

Organizations need to assess whether the performance impact of disabling simultaneous multithreading/HTT support is worthwhile relative to the risk of successful compromise of sensitive information.

Impact

Sensitive information, including cryptographic key material, may be leaked to other local users on the affected system.

The paper describing this issue and its corresponding proof-of-concept exploit make assumptions about the relative quiescence of the target system. At this stage it is unclear how viable the analysis techniques outlined in the above paper would be on busy systems.

Single user workstations and systems where users do not have the ability to run their own programs are unlikely to be affected by this specific issue.

Solution

We are not aware of an all encompassing short term solution to this issue.


Workarounds

Disabling of simultaneous multithreading/HTT support at the operating system or BIOS level may reduce the likelihood of successful attack using the methods outlined in Colin's paper, however it may not mitigate against other similar types of attackes.

Vendor Information

911878
 
Affected   Unknown   Unaffected

FreeBSD

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

FreeBSD has released a security advisory FreeBSD-SA-05:09.htt available from:

ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:09.htt.asc

FreeBSD has also released patches to disable HTT support.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Red Hat Inc.

Notified:  May 23, 2005 Updated:  August 05, 2005

Status

  Vulnerable

Vendor Statement

Vendor Statement: Red Hat, Inc

Updated packages for Red Hat Enterprise 2.1, 3, and 4 are available to mitigate this and related attacks against OpenSSL:

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

SCO

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

SCO has released two security advisories about "Hyper-Threading information leakage", they are available from:

ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.24/SCOSA-2005.24.txt
ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2005.24/SCOSA-2005.24.txt

The security advisories state:
"This issue affects OpenServer 5.0.7 if SMP is installed and any Update Pack is applied. It also affects UnixWare 7.1.4 and 7.1.3 if Hyper-Threading is enabled. (Hyper-Threading is disabled in UnixWare by default.)"

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Sun Microsystems Inc.

Notified:  May 23, 2005 Updated:  June 03, 2005

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

Sun have released a Sun(sm) Alert Notification available at:

http://sunsolve.sun.com/search/document.do?assetkey=1-26-101739-1

Sun state that Solaris on the SPARC platform is not affected by this issue.
The alert contains information on four mitigation options, see the alert for details.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

F5 Networks

Notified:  May 23, 2005 Updated:  May 26, 2005

Status

  Not Vulnerable

Vendor Statement

F5 Products are not vulnerable to VU911878, the hyperthreading information leakage issue.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Juniper Networks

Notified:  May 23, 2005 Updated:  June 02, 2005

Status

  Not Vulnerable

Vendor Statement

The hyper-threading (HTT) support in FreeBSD kernels is only
available when the kernel is configured to support symmetric
multi-processing (SMP). JUNOS is not currently configured and built
to utilize SMP for any of our platforms. Of our platforms, the
J-Series is the only one for which the hardware could physically
support HTT. There is no plan to enable HTT on the J-Series platform
for any current releases.

Juniper E-series and ScreenOS are not based on FreeBSD, and therefore
not affected.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Apple Computer Inc.

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Connectiva

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Cray Inc.

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Debian

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

EMC Corporation

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Engrade

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Fujitsu

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Hewlett-Packard Company

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Hitachi

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

IBM

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Immunix

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Ingrian Networks

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Intel

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Mandriva Inc.

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Microsoft Corporation

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

MontaVista Software

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

NEC Corporation

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

NetBSD

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Nokia

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Novell

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

OpenBSD

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Openwall GNU/*/Linux

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

QNX

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

SGI

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Sequent

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Sony Corporation

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

SuSE Inc.

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

TurboLinux

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Unisys

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

WRS

Notified:  May 23, 2005 Updated:  May 24, 2005

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

US-CERT has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Credit

Colin Percival is credited with bringing the issue to the attention of vendors and the wider community.

This document was written by Robert Mead and Chad Dougherty.

Other Information

CVE IDs: CVE-2005-0109
Severity Metric: 8.30
Date Public: 2005-05-13
Date First Published: 2005-05-23
Date Last Updated: 2005-08-05 20:29 UTC
Document Revision: 22

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.