|Summary:||CVE-2016-6258 xsa182 xen: x86: Privilege escalation in PV guests (XSA-182)|
|Product:||[Other] Security Response||Reporter:||Adam Mariš <amaris>|
|Component:||vulnerability||Assignee:||Red Hat Product Security <security-response-team>|
|Status:||CLOSED WONTFIX||QA Contact:|
|Fixed In Version:||Doc Type:||If docs needed, set a value|
A vulnerability was found Xen's MMU emulation for x86 PV guests. A malicious administrator of an x86 PV guest could control some of the page table bits, allowing potential control of memory and code execution in the host. x86 HVM and ARM guests could not exploit this flaw.
|Last Closed:||2016-07-26 13:47:48 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:||1360358|
Description Adam Mariš 2016-07-13 08:32:39 UTC
ISSUE DESCRIPTION ================= The PV pagetable code has fast-paths for making updates to pre-existing pagetable entries, to skip expensive re-validation in safe cases (e.g. clearing only Access/Dirty bits). The bits considered safe were too broad, and not actually safe. IMPACT ====== A malicous PV guest administrator can escalate their privilege to that of the host. VULNERABLE SYSTEMS ================== All versions of Xen are vulnerable. The vulnerability is only exposed to PV guests on x86 hardware. The vulnerability is not exposed to x86 HVM guests, or ARM guests. MITIGATION ========== Running only HVM guests will avoid this vulnerability. External References: http://xenbits.xen.org/xsa/advisory-182.html Acknowledgements: Name: the Xen project
Comment 3 Adam Mariš 2016-07-13 08:34:16 UTC
Created attachment 1179132 [details] xen-unstable patch
Comment 5 Adam Mariš 2016-07-26 13:45:15 UTC
Created xen tracking bugs for this issue: Affects: fedora-all [bug 1360358]
Comment 8 Fedora Update System 2016-08-05 20:54:38 UTC
xen-4.6.3-4.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.
Comment 9 Fedora Update System 2016-08-08 23:53:44 UTC
xen-4.5.3-9.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.