Bug 1848012 (CVE-2020-11019)

Summary:	CVE-2020-11019 freerdp: Out of bound read in update_recv could result in a crash
Product:	[Other] Security Response	Reporter:	Michael Kaplan <mkaplan>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	mads, mailinglists, negativo17, oholy, pahan
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	freerdp 2.1.0	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-09-29 22:01:46 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:	1848013, 1848014, 1850697, 1850699
Bug Blocks:	1848044

Description Michael Kaplan 2020-06-17 14:25:23 UTC

In FreeRDP less than or equal to 2.0.0, when running with logger set to "WLOG_TRACE", a possible crash of application could occur due to a read of an invalid array index. Data could be printed as string to local terminal. This has been fixed in 2.1.0.

References:

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-wvrr-2f4r-hjvh
https://pub.freerdp.com/cve/CVE-2020-11019/

Comment 1 Michael Kaplan 2020-06-17 14:25:48 UTC

Created freerdp tracking bugs for this issue:

Affects: fedora-all [bug 1848013]


Created freerdp1.2 tracking bugs for this issue:

Affects: fedora-all [bug 1848014]

Comment 2 Todd Cullum 2020-06-24 18:07:05 UTC

Technical Summary:

This flaw is in the update_recv() routine of libfreerdp/core/update.c. A UINT16, updateType, is parsed from the input stream and then used in an array index. There is no check in place to make sure that updateType isn't larger than the array size. If a malicious client sent a UINT16 of the improper size, it would be used to index the UPDATE_TYPE_STRINGS[] array, which would cause an out-of-bounds read. Since this read is being sent to WLog_Print, garbage data could also be entered into the log and/or printed on the server. The patch uses the update_type_to_string() routine, which only indexes the array if it will not go out-of-bounds. Since this flaw occurs during trace level logging, it is possible to mitigate the flaw by not setting the server log level to trace.

Upstream patch: https://github.com/FreeRDP/FreeRDP/commit/0332cad015fdf7fac7e5c6863484f18a554e0fcf

Comment 3 Todd Cullum 2020-06-24 18:11:39 UTC

Mitigation:

This flaw can be mitigated by not setting the logging level to "trace" on the freerdp server.

Comment 5 errata-xmlrpc 2020-09-29 20:44:16 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4031 https://access.redhat.com/errata/RHSA-2020:4031

Comment 6 Product Security DevOps Team 2020-09-29 22:01:46 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-2020-11019

Comment 7 errata-xmlrpc 2020-11-04 02:39:13 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4647 https://access.redhat.com/errata/RHSA-2020:4647