Bugzilla – Bug 1222453
VUL-0: CVE-2024-2201: xen: x86: Native Branch History Injection (XSA-456)
Last modified: 2024-07-16 16:30:15 UTC
Created attachment 874127 [details] xsa456.bundle -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Xen Security Advisory CVE-2024-2201 / XSA-456 x86: Native Branch History Injection *** EMBARGOED UNTIL 2024-04-09 17:00 UTC *** ISSUE DESCRIPTION ================= In August 2022, researchers at VU Amsterdam disclosed Spectre-BHB. Spectre-BHB was discussed in XSA-398. At the time, the susceptibility of Xen to Spectre-BHB was uncertain so no specific action was taken in XSA-398. However, various changes were made thereafter in upstream Xen as a consequence; more on these later. VU Amsterdam have subsequently adjusted the attack to be pulled off entirely from userspace, without the aid of a managed runtime in the victim context. For more details, see: https://vusec.net/projects/ XXX - TBC https://vusec.net/projects/bhi-spectre-bhb https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html https://xenbits.xen.org/xsa/advisory-398.html IMPACT ====== An attacker might be able to infer the contents of arbitrary host memory, including memory assigned to other guests. VULNERABLE SYSTEMS ================== Systems running all versions of Xen are affected. Only Intel x86 CPUs are potentially affected. CPUs from other manufacturers are not known to be affected. A wide range of Intel CPUs employ Branch History prediction techniques. However for older CPUs existing Spectre-v2 mitigations (XSA-254) are believed to be sufficient to mitigate Native-BHI. Therefore, the rest of the discussion will be limited in scope to the CPUs for which a change in behaviour is expected. These are believed to be all CPUs with eIBRS (Enhanced IBRS, a.k.a. IBRS_ALL or IBRS_ATT). eIBRS signifies a hardware adjustment (mode-tagged indirect predictions) designed to combat Spectre-v2, available in CPUs from 2019 onwards. To determine if a system has eIBRS, run `xen-cpuid -v` in dom0, looking for the string "eibrs" in the Dynamic Raw block of information. e.g. # xen-cpuid -v ... Dynamic sets: Raw ... ... [16] MSR_ARCH_CAPS.lo ... eibrs ... ... ... Be aware that the Static sets are compile time information so will include the string "eibrs" irrespective of hardware support. If there is no row for "[16] MSR_ARCH_CAPS.lo" then the fixes for XSA-435 are missing. MITIGATION ========== There are no mitigations. RESOLUTION ========== WARNING: Fixes are still in development; this is not a complete resolution!! Attached is an interim git bundle containing XSAs 454, 455, the prerequisite backports of 456 from staging, and some parts of the 456 fix which are ready. It does not contain the whole 456 fix. See https://git-scm.com/docs/git-bundle for information on git bundles. In Xen 4.17, in response to the original Spectre-BHB, CET-IBT support was added to Xen to use on capable hardware. It also came with work to remove unnecessary function pointers, and to de-virtualise function pointers at boot, as both a performance and hardening improvement. This work has been steadily continuing since, and every removed/de-virtualised function pointer reduces the options available to an adversary trying to mount a Native-BHI attack. xsa456.bundle $ sha256sum xsa456* c5a4365b0168e179da19032a3f1a4103704c19d0d2b6ab41dec7b5cb715ed30b xsa456.bundle $ DEPLOYMENT DURING EMBARGO ========================= Deployment of the patches and/or mitigations described above (or others which are substantially similar) is permitted during the embargo, even on public-facing systems with untrusted guest users and administrators. But: Distribution of updated software is prohibited (except to other members of the predisclosure list). Predisclosure list members who wish to deploy significantly different patches and/or mitigations, please contact the Xen Project Security Team. (Note: this during-embargo deployment notice is retained in post-embargo publicly released Xen Project advisories, even though it is then no longer applicable. This is to enable the community to have oversight of the Xen Project Security Team's decisionmaking.) For more information about permissible uses of embargoed information, consult the Xen Project community's agreed Security Policy: http://www.xenproject.org/security-policy.html -----BEGIN PGP SIGNATURE----- iQFABAEBCAAqFiEEI+MiLBRfRHX6gGCng/4UyVfoK9kFAmYQLa0MHHBncEB4ZW4u b3JnAAoJEIP+FMlX6CvZWLwIAMJKBUxZWY+C/D64Odg39DTtr7Xm6QaY4qTKYt2/ Uc3RDx8s0akSVCTmdSk+KgSPrbknpqJQxEihREoEWWJB6ACe6O31Fg9LQVeFfxVc ed7I2fmNtItZLZD4cta0OXBKAOWPkYO/yab3uOvZ/ESWT3WP5XfCU2I63lJzan35 M0mDWuIOD/3J9+Kne0+pTZl+XZoxiXbtxAeQCkU4MCQXU/UFVAz+f5f/FGR4AJE7 AcY3fmvHVk0E2jD+sqxtJ7AliA29hS53R+Z4Ziyd8kYp3rx6cNSYgtg9A7h6rf6e ELwwvGJfphtQH+Qb4C5lBc3jnjGSybxqbq3FcR1xJHc9Yjw= =2JqO -----END PGP SIGNATURE-----
This is an autogenerated message for OBS integration: This bug (1222453) was mentioned in https://build.opensuse.org/request/show/1166538 Factory / xen
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SUSE-SU-2024:1259-1: An update that solves three vulnerabilities and has one security fix can now be installed. Category: security (moderate) Bug References: 1027519, 1221984, 1222302, 1222453 CVE References: CVE-2023-46842, CVE-2024-2201, CVE-2024-31142 Maintenance Incident: [SUSE:Maintenance:33341](https://smelt.suse.de/incident/33341/) Sources used: openSUSE Leap 15.4 (src): xen-4.16.6_02-150400.4.55.1 openSUSE Leap Micro 5.3 (src): xen-4.16.6_02-150400.4.55.1 openSUSE Leap Micro 5.4 (src): xen-4.16.6_02-150400.4.55.1 SUSE Linux Enterprise Micro for Rancher 5.3 (src): xen-4.16.6_02-150400.4.55.1 SUSE Linux Enterprise Micro 5.3 (src): xen-4.16.6_02-150400.4.55.1 SUSE Linux Enterprise Micro for Rancher 5.4 (src): xen-4.16.6_02-150400.4.55.1 SUSE Linux Enterprise Micro 5.4 (src): xen-4.16.6_02-150400.4.55.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
SUSE-SU-2024:1295-1: An update that solves three vulnerabilities and has one security fix can now be installed. Category: security (moderate) Bug References: 1027519, 1221984, 1222302, 1222453 CVE References: CVE-2023-46842, CVE-2024-2201, CVE-2024-31142 Maintenance Incident: [SUSE:Maintenance:33340](https://smelt.suse.de/incident/33340/) Sources used: openSUSE Leap 15.5 (src): xen-4.17.4_02-150500.3.30.1 SUSE Linux Enterprise Micro 5.5 (src): xen-4.17.4_02-150500.3.30.1 Basesystem Module 15-SP5 (src): xen-4.17.4_02-150500.3.30.1 Server Applications Module 15-SP5 (src): xen-4.17.4_02-150500.3.30.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
SUSE-SU-2024:1541-1: An update that solves three vulnerabilities and has one security fix can now be installed. Category: security (moderate) Bug References: 1027519, 1221984, 1222302, 1222453 CVE References: CVE-2023-46842, CVE-2024-2201, CVE-2024-31142 Maintenance Incident: [SUSE:Maintenance:33626](https://smelt.suse.de/incident/33626/) Sources used: SUSE Linux Enterprise Software Development Kit 12 SP5 (src): xen-4.12.4_48-3.109.1 SUSE Linux Enterprise Server for SAP Applications 12 SP5 (src): xen-4.12.4_48-3.109.1 SUSE Linux Enterprise High Performance Computing 12 SP5 (src): xen-4.12.4_48-3.109.1 SUSE Linux Enterprise Server 12 SP5 (src): xen-4.12.4_48-3.109.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
SUSE-SU-2024:1540-1: An update that solves three vulnerabilities can now be installed. Category: security (moderate) Bug References: 1221984, 1222302, 1222453 CVE References: CVE-2023-46842, CVE-2024-2201, CVE-2024-31142 Maintenance Incident: [SUSE:Maintenance:33625](https://smelt.suse.de/incident/33625/) Sources used: openSUSE Leap 15.3 (src): xen-4.14.6_14-150300.3.72.1 SUSE Linux Enterprise Micro 5.1 (src): xen-4.14.6_14-150300.3.72.1 SUSE Linux Enterprise Micro 5.2 (src): xen-4.14.6_14-150300.3.72.1 SUSE Linux Enterprise Micro for Rancher 5.2 (src): xen-4.14.6_14-150300.3.72.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Xen Security Advisory CVE-2024-2201 / XSA-456 version 3 x86: Native Branch History Injection UPDATES IN VERSION 3 ==================== Issues were found with the original code changes. See the bottom of the Resolution section for how to obtain those. [...] RESOLUTION ========== [...] Issues were in those found subsequently. To address those, newer commits from the stable branches need updating to, in particular stable-4.15 056500003eb44314cb90f2e3e7b2d405e86b5657 stable-4.16 d0e8f8ffbb19b5df5f767328baeb54c069b08e6a stable-4.17 effcf70f020ff12d34c80e2abde0ecb00ce92bda stable-4.18 f0ff1d9cb96041a84a24857a6464628240deed4f For 4.15, since we're closing the branch, RELEASE-4.15.7 was tagged in addition; other release activities - as per above - will follow.
SUSE-SU-2024:2535-1: An update that solves six vulnerabilities and has one security fix can now be installed. Category: security (important) Bug References: 1214083, 1221332, 1221334, 1221984, 1222302, 1222453, 1227355 CVE References: CVE-2023-28746, CVE-2023-46842, CVE-2024-2193, CVE-2024-2201, CVE-2024-31142, CVE-2024-31143 Maintenance Incident: [SUSE:Maintenance:33138](https://smelt.suse.de/incident/33138/) Sources used: SUSE Linux Enterprise High Performance Computing 15 SP2 LTSS 15-SP2 (src): xen-4.13.5_12-150200.3.93.1 SUSE Linux Enterprise Server 15 SP2 LTSS 15-SP2 (src): xen-4.13.5_12-150200.3.93.1 SUSE Linux Enterprise Server for SAP Applications 15 SP2 (src): xen-4.13.5_12-150200.3.93.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
SUSE-SU-2024:2534-1: An update that solves two vulnerabilities and has one security fix can now be installed. Category: security (important) Bug References: 1027519, 1222453, 1227355 CVE References: CVE-2024-2201, CVE-2024-31143 Maintenance Incident: [SUSE:Maintenance:34727](https://smelt.suse.de/incident/34727/) Sources used: SUSE Linux Enterprise Software Development Kit 12 SP5 (src): xen-4.12.4_50-3.112.1 SUSE Linux Enterprise Server for SAP Applications 12 SP5 (src): xen-4.12.4_50-3.112.1 SUSE Linux Enterprise High Performance Computing 12 SP5 (src): xen-4.12.4_50-3.112.1 SUSE Linux Enterprise Server 12 SP5 (src): xen-4.12.4_50-3.112.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
SUSE-SU-2024:2533-1: An update that solves two vulnerabilities can now be installed. Category: security (important) Bug References: 1222453, 1227355 CVE References: CVE-2024-2201, CVE-2024-31143 Maintenance Incident: [SUSE:Maintenance:34726](https://smelt.suse.de/incident/34726/) Sources used: openSUSE Leap 15.3 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise High Performance Computing LTSS 15 SP3 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise Server 15 SP3 LTSS 15-SP3 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise Server for SAP Applications 15 SP3 (src): xen-4.14.6_16-150300.3.75.1 SUSE Enterprise Storage 7.1 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise Micro 5.1 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise Micro 5.2 (src): xen-4.14.6_16-150300.3.75.1 SUSE Linux Enterprise Micro for Rancher 5.2 (src): xen-4.14.6_16-150300.3.75.1 NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.