Bug 1850549 (CVE-2020-12866)

Summary:	CVE-2020-12866 sane-backends: null pointer dereference in epsonds_net_read in epsonds-net.c
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	mike, nphilipp, thibault.north, zdohnal
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	sane-backends 1.0.30	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	1850550, 1850551, 1852664
Bug Blocks:	1848100

Description Pedro Sampaio 2020-06-24 13:29:30 UTC

A flaw was found in sane-backends before version 1.0.30. A null pointer dereference issue in function epsonds_net_read may lead to remote denial of service.

Upstream issue:

https://gitlab.com/sane-project/backends/-/issues/279#issue-2-ghsl-2020-079-null-pointer-dereference-in-epsonds_net_read

References:

https://gitlab.com/sane-project/backends/-/releases

Comment 1 Pedro Sampaio 2020-06-24 13:29:54 UTC

Created mingw-sane-backends tracking bugs for this issue:

Affects: fedora-all [bug 1850551]


Created sane-backends tracking bugs for this issue:

Affects: fedora-all [bug 1850550]

Comment 2 Huzaifa S. Sidhpurwala 2020-07-01 03:38:59 UTC

Statement:

The vulnerable code is a part of "driver for Epson ESC/I-2 scanners" which was first introduced in sane-backends-1.0.25. (via https://gitlab.com/sane-project/backends/-/commit/d72f4663c0ad6e6f779c15c8baf5f92b675ae19a)  Therefore only versions of sane-backends shipped with Red Hat Enterprise Linux 8 is affected by this flaw.

Comment 4 Huzaifa S. Sidhpurwala 2020-07-01 03:41:15 UTC

External References:

https://gitlab.com/sane-project/backends/-/issues/279#issue-2-ghsl-2020-079-null-pointer-dereference-in-epsonds_net_read

Comment 5 Huzaifa S. Sidhpurwala 2020-07-01 04:42:24 UTC

Mitigation:

This flaw can be mitigated by limiting network scanner discovery to a trusted subnet via the "net" configuration in the "/etc/sane.d/epsonds.conf" configuration file. Also automatic network scanner discovery can be turned off by commenting out the line "net autodiscovery" in the same configuration file.