Bug 1819163 (CVE-2020-10701)

Summary: CVE-2020-10701 libvirt: guest agent timeout can be set under read-only mode leading to DoS
Product: [Other] Security Response Reporter: Marian Rehak <mrehak>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: agedosier, berrange, clalancette, eblake, itamar, jdenemar, jforbes, jsuchane, knoel, laine, libvirt-maint, pkrempa, security-response-team, veillard, virt-maint, virt-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: libvirt 6.2.0 Doc Type: If docs needed, set a value
Doc Text:
A missing authorization flaw was found in the libvirt API responsible for changing the QEMU agent response timeout. This flaw allows read-only connections to adjust the time that libvirt waits for the QEMU guest agent to respond to agent commands. Depending on the timeout value that is set, this flaw can make guest agent commands fail because the agent cannot respond in time. Unprivileged users with a read-only connection could abuse this flaw to set the response timeout for all guest agent messages to zero, potentially leading to a denial of service.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2020-04-02 16:32:06 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1819164    

Description Marian Rehak 2020-03-31 11:11:55 UTC 
A bug was reported internally about a bug in libvirt allowing a user on a read-only to change the response timeout for all guest agent messages. Changing this timeout can potentially cause some commands to fail.
Comment 3 Mauro Matteo Cascella 2020-04-02 11:13:20 UTC 
Statement:

This flaw did not affect the versions of `libvirt` as shipped with Red Hat Enterprise Linux 5, 6, 7, 8 and RHEL Advanced Virtualization, as they did not include the vulnerable code, which was introduced in a later version of the package. Specifically, `libvirt` API to change QEMU agent response timeout was added in `libvirt` upstream version v5.10.0.
Comment 4 Mauro Matteo Cascella 2020-04-02 13:46:32 UTC 
Upstream fix:
https://libvirt.org/git/?p=libvirt.git;a=commit;h=4cc90c2e62df653e909ad31fd810224bf8bcf913
Comment 6 Mauro Matteo Cascella 2020-04-03 14:37:08 UTC 
Acknowledgments:

Name: Lili Zhu (Red Hat)