Bug 2036966 (CVE-2021-4207) - CVE-2021-4207 QEMU: QXL: double fetch in qxl_cursor() can lead to heap buffer overflow
Summary: CVE-2021-4207 QEMU: QXL: double fetch in qxl_cursor() can lead to heap buffer...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2021-4207
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2040736 2040737 2040738 2040739 2070895 2070896 2075683
Blocks: 2040475 2054405
TreeView+ depends on / blocked
 
Reported: 2022-01-04 14:21 UTC by Pedro Sampaio
Modified: 2024-03-29 09:20 UTC (History)
33 users (show)

Fixed In Version: qemu-kvm 7.0.0
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and `cursor->header.height` can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.
Clone Of:
Environment:
Last Closed: 2022-08-31 02:55:52 UTC
Embargoed:

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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2022:5002 0 None None None 2022-06-13 11:51:32 UTC
Red Hat Product Errata RHSA-2022:5821 0 None None None 2022-08-02 10:01:05 UTC

Description Pedro Sampaio 2022-01-04 14:21:07 UTC 
In the QEMU QXL video acelerator a double fetch leads to heap overflow in qxl_unpack_chunks function.
Comment 5 Mauro Matteo Cascella 2022-04-01 10:09:28 UTC 
Created qemu tracking bugs for this issue:

Affects: epel-7 [bug 2070896]
Affects: fedora-all [bug 2070895]
Comment 6 Mauro Matteo Cascella 2022-04-01 10:21:10 UTC 
STAR Labs security advisory: https://starlabs.sg/advisories/21/21-4207.
Comment 7 Salvatore Bonaccorso 2022-04-07 04:28:16 UTC 
Hi

Is CVE-2021-4207 as assignment correct? The bugzilla entry say CVE-2021-4207 while https://starlabs.sg/advisories/22-4207/ say it's CVE-2022-4207. I assume this was Red Hat assigned and so given the disclosure timeline as well mentioned in the blog article the 2021 one is the correct one?
Comment 8 Mauro Matteo Cascella 2022-04-07 08:02:05 UTC 
You're right, CVE-2021-4207 is the correct CVE id. I asked them to update the security advisory accordingly. Thank you for the heads up.
Comment 9 Salvatore Bonaccorso 2022-04-07 19:25:50 UTC 
(In reply to Mauro Matteo Cascella from comment #8)
> You're right, CVE-2021-4207 is the correct CVE id. I asked them to update
> the security advisory accordingly. Thank you for the heads up.

Hi Mauro. Thanks for confirming it as well here!

Regards,
Salvatore
Comment 11 Mauro Matteo Cascella 2022-04-08 15:38:23 UTC 
In reply to comment #7:
> Is CVE-2021-4207 as assignment correct? The bugzilla entry say CVE-2021-4207
> while https://starlabs.sg/advisories/22-4207/ say it's CVE-2022-4207.

The fixed advisory is 21-4207 which is now listed on the main Advisories page: https://starlabs.sg/advisories. The same holds for 21-4206 (bz#2036998). The obsolete 22-4206 and 22-4207 are not listed anymore but unfortunately they are still accessible with direct link.
Comment 12 Mauro Matteo Cascella 2022-04-08 15:39:19 UTC 
Upstream fix:
https://gitlab.com/qemu-project/qemu/-/commit/9569f5cb
Comment 13 errata-xmlrpc 2022-06-13 11:51:28 UTC 
This issue has been addressed in the following products:

  Advanced Virtualization for RHEL 8.4.0.EUS

Via RHSA-2022:5002 https://access.redhat.com/errata/RHSA-2022:5002
Comment 14 errata-xmlrpc 2022-08-02 10:01:02 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:5821 https://access.redhat.com/errata/RHSA-2022:5821
Comment 15 Product Security DevOps Team 2022-08-31 02:55:49 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-2021-4207
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