We have just published Qubes Security Bulletin (QSB) #061: Information leak via power sidechannel (XSA-351). The text of this QSB is reproduced below. This QSB and its accompanying signatures will always be available in the Qubes Security Pack (qubes-secpack).
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---===[ Qubes Security Bulletin #61 ]===--- 2020-11-10 Information leak via power sidechannel (XSA-351) Summary ======== On 2020-11-10, the Xen Security Team published Xen Security Advisory 351 (XSA-351)  with the following description: | Researchers have demonstrated using software power/energy monitoring | interfaces to create covert channels, and infer the operations/data used | by other contexts within the system. | | Access to these interfaces should be restricted to privileged software, | but it was found that Xen doesn't restrict access suitably, and the | interfaces are accessible to all guests. | | For more information, see: | https://platypusattack.com | https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00389.html | | An unprivileged guest administrator can sample platform power/energy | data. This may be used to infer the operations/data used by other | contexts within the system. | | The research demonstrates using this sidechannel to leak the AES keys | used elsewhere in the system. Patching ========= The specific packages that resolve the problems discussed in this bulletin are as follows: For Qubes 4.0: - Xen packages, version 4.8.5-26 For Qubes 4.1: - Xen packages, version 4.14.0-7 The packages are to be installed in dom0 via the Qube Manager or via the qubes-dom0-update command as follows: For updates from the stable repository (not immediately available): $ sudo qubes-dom0-update For updates from the security-testing repository: $ sudo qubes-dom0-update --enablerepo=qubes-dom0-security-testing A system restart will be required afterwards. These packages will migrate from the security-testing repository to the current (stable) repository over the next two weeks after being tested by the community. If you use Anti Evil Maid, you will need to reseal your secret passphrase to new PCR values, as PCR18+19 will change due to the new Xen binaries. Credits ======== See the original Xen Security Advisory. References ===========  https://xenbits.xen.org/xsa/advisory-351.html -- The Qubes Security Team https://www.qubes-os.org/security/
This is a companion discussion topic for the original entry at https://www.qubes-os.org/news/2020/11/10/qsb-061/