Bug 2050324 (CVE-2022-0485)

Summary:	CVE-2022-0485 libnbd: nbdcopy: missing error handling may create corrupted destination image
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	eblake, lersek, rjones, virt-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libnbd 1.11.8	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the copying tool `nbdcopy` of libnbd. When performing multi-threaded copies using asynchronous nbd calls, nbdcopy was blindly treating the completion of an asynchronous command as successful, rather than checking the *error parameter. This could result in the silent creation of a corrupted destination image.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-12 09:45:44 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:	2045718, 2046194, 2050325, 2050338, 2050339, 2050340
Bug Blocks:	2050309, 2050326

Description Mauro Matteo Cascella 2022-02-03 17:02:34 UTC

A flaw was found in nbdcopy. When copying from NBD server using the asynchronous copy mode (default) nbdcopy may create a corrupted destination image if read or write NBD command start but the server returns an error. nbdcopy also exits with zero exit code, so programs running it cannot detect that the operation failed.

Upstream patch proposed:
https://listman.redhat.com/archives/libguestfs/2022-February/msg00039.html

Comment 1 Mauro Matteo Cascella 2022-02-03 17:03:14 UTC

Created libnbd tracking bugs for this issue:

Affects: fedora-all [bug 2050325]

Comment 9 Richard W.M. Jones 2022-02-04 08:57:50 UTC

Thanks!

Comment 11 Mauro Matteo Cascella 2022-02-07 13:57:05 UTC

Patch v2:
https://listman.redhat.com/archives/libguestfs/2022-February/msg00059.html

Comment 12 Mauro Matteo Cascella 2022-02-07 14:00:51 UTC

Upstream commit:
https://gitlab.com/nbdkit/libnbd/-/commit/8d444b41d09a700c7ee6f9182a649f3f2d325abb

Comment 14 Mauro Matteo Cascella 2022-02-07 21:05:32 UTC

Libnbd security advisory:
https://listman.redhat.com/archives/libguestfs/2022-February/msg00104.html

Comment 15 errata-xmlrpc 2022-03-16 14:07:57 UTC

This issue has been addressed in the following products:

  Advanced Virtualization for RHEL 8.5.0.Z

Via RHSA-2022:0949 https://access.redhat.com/errata/RHSA-2022:0949

Comment 16 errata-xmlrpc 2022-03-21 07:52:11 UTC

This issue has been addressed in the following products:

  Advanced Virtualization for RHEL 8.4.0.EUS

Via RHSA-2022:0971 https://access.redhat.com/errata/RHSA-2022:0971

Comment 17 errata-xmlrpc 2022-05-10 13:17:59 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1759 https://access.redhat.com/errata/RHSA-2022:1759

Comment 18 errata-xmlrpc 2022-05-11 10:47:44 UTC

This issue has been addressed in the following products:

  Advanced Virtualization for RHEL 8.6.0

Via RHSA-2022:2181 https://access.redhat.com/errata/RHSA-2022:2181

Comment 19 Product Security DevOps Team 2022-05-12 09:45:42 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-2022-0485

Comment 20 Richard W.M. Jones 2022-07-06 12:59:36 UTC

A simple reproducer for this is:

nbdcopy -p -- [ nbdkit --filter=error pattern 5M error-pread-rate=1 ] null:

This command will exit with success (status code 0) if the bug is present
and exit with an error (status code 1) if the bug is fixed.

Note that nbdkit error messages will be printed either way.

Comment 21 Mauro Matteo Cascella 2022-12-01 10:16:30 UTC

As far as Red Hat CVSS score is concerned, this is a data corruption issue with integrity impact (for a failed read by source NBD server) and confidentiality impact (for a failed write by destination NBD server). In both cases Low impact (C:L/I:L) as the attacker has no control over what information is modified/obtained. No direct compromise of availability (A:N).