Bug 1854843 (CVE-2020-11098)

Summary:	CVE-2020-11098 freerdp: out-of-bound read in glyph_cache_put
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
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, negativo17, oholy, pahan
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	freerdp 2.1.2	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-05-18 20:34:03 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:	1854844, 1854845, 1855864, 1855865
Bug Blocks:	1854906

Description Dhananjay Arunesh 2020-07-08 11:07:57 UTC

In FreeRDP before version 2.1.2, there is an out-of-bound read in glyph_cache_put. This affects all FreeRDP clients with `+glyph-cache` option enabled This is fixed in version 2.1.2.

References:
http://www.freerdp.com/2020/06/22/2_1_2-released
https://github.com/FreeRDP/FreeRDP/commit/c0fd449ec0870b050d350d6d844b1ea6dad4bc7d
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-jr57-f58x-hjmv

Comment 1 Dhananjay Arunesh 2020-07-08 11:10:11 UTC

Created freerdp tracking bugs for this issue:

Affects: epel-all [bug 1854845]
Affects: fedora-all [bug 1854844]

Comment 3 Todd Cullum 2020-07-10 18:06:13 UTC

glyph_cache_put() in libfreerdp/cache/glyph.c has an off-by-one indexing error which allows glyphCache->glyphCache[id].entries[index] to be indexed out-of-bounds. The patch ensures that index is less than glyphCache->glyphCache[id].number which avoids the out-of-bounds read. Marking this as Low because the feature is disabled by default and there is a low risk to availability in the freerdp client only.

Comment 4 Todd Cullum 2020-07-10 18:15:48 UTC

Mitigation:

Do not use the +glyph_cache option in the freerdp client, which is disabled by default in freerdp-2.0.0.rc4 (shipped with Red Hat Enterprise Linux 7 and 8), but required to connect to xrdp.

Comment 6 errata-xmlrpc 2021-05-18 15:34:08 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1849 https://access.redhat.com/errata/RHSA-2021:1849

Comment 7 Product Security DevOps Team 2021-05-18 20:34:03 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-2020-11098