From ${URL} : Xen Security Advisory CVE-2014-4021 / XSA-100 version 3 Hypervisor heap contents leaked to guests UPDATES IN VERSION 3 ==================== Public Release. CVE assigned. ISSUE DESCRIPTION ================= While memory pages recovered from dying guests are being cleaned to avoid leaking sensitive information to other guests, memory pages that were in use by the hypervisor and are eligible to be allocated to guests weren't being properly cleaned. Such exposure of information would happen through memory pages freshly allocated to or by the guest. Normally the leaked data is administrative information of limited value to an attacker. However, scenarios exist where guest CPU register state and hypercall arguments might be leaked. IMPACT ====== A malicious guest might be able to read data relating to other guests or the hypervisor itself. Data at rest in guest memory or storage (filesystems) is not affected. However, it is possible for an attacker to obtain modest amounts of in-flight and in-use data, which might contain passwords or cryptographic keys. VULNERABLE SYSTEMS ================== Xen 3.2.x and later are vulnerable. Xen 3.1.x and earlier have not been inspected. MITIGATION ========== No comprehensive mitigation is available. An attacker will find it easier obtain sensitive data from a victim guest if the attacker is able to initiate domain management operations and lifecycle events for that guest. This includes a situation where the attacker can cause the victim guest to crash. Therefore the risk from this vulnerability can be somewhat reduced by restricting management (such as migration or resource adjustment) to fully trusted guest or host administrators, and by eliminating any Denial of Service vulnerabilities against potential victim guests. CREDITS ======= This issue was discovered by Jan Beulich. RESOLUTION ========== Applying the attached patch resolves this issue. xsa100.patch xen-unstable, Xen 4.4.x, Xen 4.3.x, Xen 4.2.x, Xen 4.1.x Note that to avoid a regression on systems with AMD IOMMU, on 4.2.x and later additionally commit 6b4d71d0 ("AMD IOMMU: don't free page table prematurely") found at http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=6b4d71d028f445cba7426a144751fddc8bfdd67b will be required if not already in place in the respective tree. @maintainer(s): after the bump, in case we need to stabilize the package, please let us know if it is ready for the stabilization or not.
+*xen-4.4.0-r5 (09 Jul 2014) +*xen-4.3.2-r4 (09 Jul 2014) +*xen-4.2.4-r4 (09 Jul 2014) + + 09 Jul 2014; Yixun Lan <dlan@gentoo.org> +xen-4.2.4-r4.ebuild, + +xen-4.3.2-r4.ebuild, +xen-4.4.0-r5.ebuild: + bump stable/security patches, fix bug 515106, 513824
dlan, As per discussion please either call for stabilization, or advise when ready for stabilization.
Arches, please test and mark stable: =app-emulation/xen-4.2.4-r4 =app-emulation/xen-tools-4.2.4-r6 Target keywords Both : "amd64 x86" =app-emulation/xen-4.3.2-r4 =app-emulation/xen-tools-4.3.2-r5 Target keywords Only: "amd64"
amd64 stable
x86 stable. Maintainer(s), please cleanup. Security, please vote.
thanks, old versions have been pruned out.
Arches and Maintainer(s), Thank you for your work. GLSA Vote: Yes
CVE-2014-4021 (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2014-4021): Xen 3.2.x through 4.4.x does not properly clean memory pages recovered from guests, which allows local guest OS users to obtain sensitive information via unspecified vectors.
Added to an existing GLSA request.
This issue was resolved and addressed in GLSA 201407-03 at http://security.gentoo.org/glsa/glsa-201407-03.xml by GLSA coordinator Mikle Kolyada (Zlogene).
