Bug 1823913 (CVE-2020-11741)

Summary: CVE-2020-11741 xen: xenoprof issue allows guest OS users with active profiling to obtain sensitive information about other guests (XSA-313)
Product: [Other] Security Response Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED WONTFIX QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: acaringi, ailan, bhu, brdeoliv, dhoward, drjones, dvlasenk, fhrbata, hkrzesin, imammedo, jforbes, jshortt, jstancek, knoel, m.a.young, mrezanin, nmurray, pbonzini, robinlee.sysu, rvrbovsk, vkuznets, xen-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in Xenoprof in the Xen virtual machine through version 4.13.x, where it allows guest OS users, with active profiling, to obtain sensitive information about other guests, cause a denial of service, or possibly gain privileges. For guests with “active” profiling enabled by the administrator, the Xenoprof code uses the standard Xen shared ring structure. With this flaw, the code does not treat the guest as a potential attacker, and it trusts the guest not to modify the buffer size information and not modify the head/tail pointers in unexpected ways, which can lead to a denial of service or escalation of privileges.
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Clone Of: Environment:
Last Closed: 2020-04-16 15:47:47 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1823914    
Bug Blocks: 1823917    

Description Guilherme de Almeida Suckevicz 2020-04-14 19:11:40 UTC 
An issue was discovered in xenoprof in Xen through 4.13.x, allowing guest OS users (with active profiling) to obtain sensitive information about other guests, cause a denial of service, or possibly gain privileges. For guests for which "active" profiling was enabled by the administrator, the xenoprof code uses the standard Xen shared ring structure. Unfortunately, this code did not treat the guest as a potential adversary: it trusts the guest not to modify buffer size information or modify head / tail pointers in unexpected ways. This can crash the host (DoS). Privilege escalation cannot be ruled out.

Reference:
https://xenbits.xen.org/xsa/advisory-313.html
Comment 1 Guilherme de Almeida Suckevicz 2020-04-14 19:12:00 UTC 
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1823914]