Bug 1879567 (CVE-2020-25599) - CVE-2020-25599 xen: races with evtchn_reset function (XSA-343)
Summary: CVE-2020-25599 xen: races with evtchn_reset function (XSA-343)
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2020-25599
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1881581
Blocks: 1877386
TreeView+ depends on / blocked
 
Reported: 2020-09-16 14:24 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-02-16 19:15 UTC (History)
25 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in Xen. Uses of EVTCHNOP_reset or XEN_DOMCTL_soft_reset can lead to the violation of various internal assumptions leading to an out of bounds memory access or triggering of bug checks. In particular x86 PV guests may be able to elevate their privilege to that of the host. Information leaks cannot be ruled out and host and guest crashes are also possible, leading to a denial of service (DoS). The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Clone Of:
Environment:
Last Closed: 2020-09-22 20:41:30 UTC
Embargoed:

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Description Guilherme de Almeida Suckevicz 2020-09-16 14:24:39 UTC 
Uses of EVTCHNOP_reset (potentially by a guest on itself) or XEN_DOMCTL_soft_reset (by itself covered by XSA-77) can lead to the violation of various internal assumptions. This may lead to out of bounds memory accesses or triggering of bug checks.
Comment 1 Mauro Matteo Cascella 2020-09-16 16:10:11 UTC 
Acknowledgments:

Name: the Xen project
Comment 2 Mauro Matteo Cascella 2020-09-17 13:31:17 UTC 
Statement:

All Xen versions from 4.4 onwards are vulnerable. Red Hat Enterprise Linux 5 is not affected by this flaw, as it shipped an older version of Xen.
Comment 3 Mauro Matteo Cascella 2020-09-17 13:31:19 UTC 
Mitigation:

There is no known mitigation for this flaw apart from applying the patch.
Comment 4 Mauro Matteo Cascella 2020-09-22 17:48:14 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1881581]
Comment 5 Product Security DevOps Team 2020-09-22 20:41:30 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-25599
Comment 6 Mauro Matteo Cascella 2020-09-23 07:36:39 UTC 
External References:

https://xenbits.xen.org/xsa/advisory-343.html
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