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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.4023 Information leak via power sidechannel 12 November 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Xen Publisher: Xen Operating System: Xen Impact/Access: Access Confidential Data -- Remote/Unauthenticated Resolution: Patch/Upgrade Reference: ESB-2020.3964 Original Bulletin: http://xenbits.xen.org/xsa/advisory-351.html - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Xen Security Advisory XSA-351 Information leak via power sidechannel ISSUE 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 IMPACT ====== 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. VULNERABLE SYSTEMS ================== Power/energy monitoring interfaces are platform and architecture specific. Consult your hardware vendor to ascertain what power feedback interfaces are available. For ARM systems, all versions of Xen are vulnerable. The fix restricts access to the AMU (Activity Monitors Unit) interface, introduced in Armv8.4. For x86 systems, Xen 4.14 and earlier are vulnerable - master is not vulnerable, as these issues have been addressed in a more general fashion. The x86 fixes restrict access to: * Intel RAPL interface, introduced in SandyBridge CPUs. * Intel platform energy interface. * Intel perf_ctl interface, introduced in Pentium 4 CPUs and also implemented by other vendors. * AMD RAPL interface, introduced in Ryzen/EPYC CPUs. * AMD compute unit energy interface, present in Fam15/16 CPUs. MITIGATION ========== There are no mitigations available. RESOLUTION ========== Applying the appropriate attached patch resolves this issue. Note that patches for released versions are generally prepared to apply to the stable branches, and may not apply cleanly to the most recent release tarball. Downstreams are encouraged to update to the tip of the stable branch before applying these patches. xsa351-arm.patch Xen unstable - 4.10.x [ARM] xsa351-x86-4.14-.patch Xen 4.14.x [x86] xsa351-x86-4.13-.patch Xen 4.13.x [x86] xsa351-x86-4.12-.patch Xen 4.12.x [x86] xsa351-x86-4.11-.patch Xen 4.11.x - 4.10.x [x86] $ sha256sum xsa351* cad287981a870f13484834fa2364ffee68178517e906f55d2889304a4a9eae06 xsa351.meta 70ebd0e93af240af2680374dcfd8ff4a5dd3eefccf670f1cb9b546d763d6a554 xsa351-arm.patch 49b52a1366912a29e184e3014a9f1f579e8a0dd8a36f01d38d995d2c8ed81928 xsa351-arm-4.11.patch 2e7b7c2b98625d70c8b10047a9f668372f3ccede167344dedb712312606acbca xsa351-x86-4.11-1.patch ab9e2cb7d5e3e0c3a916f006c697495f4f01146e09df60ece59ce0a8f7aa5ed0 xsa351-x86-4.11-2.patch bb68f6e6905bc1566156cafab058cbaf02a17c197385c33a83b7f73885913c1c xsa351-x86-4.12-1.patch 53f464269f59498f8a9a614f10a47cfb1d81c666f0d684346e28005015de962c xsa351-x86-4.12-2.patch 67a29d66230faafd9a8047ac80ec18130b5659e80a38c3a412cb2be6d3288a8f xsa351-x86-4.13-1.patch f7d8717dec33ee7484b36490402d113f1e7e168e7541bcf193fef620df299f08 xsa351-x86-4.13-2.patch 7d4fbe11a766226d7f1b93c5bf34664d8855deee09d1feebc76f11e49f2aa9c9 xsa351-x86-4.14-1.patch 41df825deafe3ef28e8594ec956033689af69f84a4a6dd92f97d1071e925203d xsa351-x86-4.14-2.patch $ NOTE REGARDING LACK OF EMBARGO ============================== Despite an attempt to organise predisclosure, the discoverers ultimately did not authorise a predisclosure. - -----BEGIN PGP SIGNATURE----- iQFABAEBCAAqFiEEI+MiLBRfRHX6gGCng/4UyVfoK9kFAl+q1WwMHHBncEB4ZW4u b3JnAAoJEIP+FMlX6CvZANkH+wf8pft4t9KoC9HFxd96DfCjZ+FQnD0hMp+890cY ztNJM4+o+SBP2ytEMZLIoN1oJeTSQqyNgQh2sXNm7/WpseklOTR6s8zw4LWATEfz rqF8G2xIN8ka7AAqAwOzkzj6qlxuWbiXKm4ENd5ocRxVvF1A2PYyEX88uCPgmupg dqfufhYQF7hrz8VKDRDYtLsMrRaIFCWqGdOdQfVF64pHGHLvGZkANGN8yva8mBfC uavwvX+O3CdVMENS4AA3TNo6p2nnWp1iQJCiBwLGCRbTQaRtRucV4Q/eSLC3pHLp NO26OxieT4tLJN7Ox4ex43KZIsyweZSaUl18rfg0J8MB3FM= =/6Fo - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBX6yru+NLKJtyKPYoAQioJxAAri2vxMIpWzITrOb4WL60mBkeXWli/HoN XXvqMKXKoFTkuAMc6tJwySsPsIuLa3LvIze4GUGCsPIzrkN8ElRb95zoh805AOGy YjvOSxOPZzQ3yOqkzDhmO5BWth07NfR9I/WI4xLbgtz4QIkLxAHfTxkx7waAQBMq 8M1EnMkIZbJ1TFtdkF2OOsCnNZu/bQSQCO0InnLl4a2XOSh819kCz0QX/hTPxuPp uDUGNv3+V5PMEDsug6TL9WKYx7b06hZANwZqgbVX9Oac4cdmTctYsj9O0/SFGyjC 6JwwuhKIj0DNMNmLuqQ83DmYhOQRT865hAxDQ1br+tLGwLczgnwgxBpIvI0z1phc FfUcTNQ1Iz1CXFEIRYXgw95dOZb6oZOw5Ghrmkabcl7K5m3tx2ExABHZcTHqAFwp bvg3IGNkx/2KKHhFyKQkMhPJ0tBS3Qj29UC5yYMsJwCvxxbMNYrFQm84G844hjfG sy9EKNicJGL5OioCM4nZs+JeAQpy63NL7i8p/dchtzy9/2wUindh9JCyAH/Amxlw zKJnopnkyjwIjNi5zrvSrA8bW0Y7+EoSJiUu1zIx/n6LbK8EJu79qxLmod0Aktz6 XCxwJZgE/tlI0l+v7wVilwlvsbcmqJAPTYwhZ/JZNBe8Br7yXR5efL1VelN3kjWy HgyX3K0HOLQ= =+vaL -----END PGP SIGNATURE-----