Bug 1844161 (CVE-2020-11085) - CVE-2020-11085 freerdp: out-of-bounds read in cliprdr_read_format_list function
Summary: CVE-2020-11085 freerdp: out-of-bounds read in cliprdr_read_format_list function
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-11085
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1844162 1844163 1844164 1844165 1844282 1844283
Blocks: 1844196
TreeView+ depends on / blocked
 
Reported: 2020-06-04 18:11 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-02-16 19:56 UTC (History)
4 users (show)

Fixed In Version: freerdp 2.1.0
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2020-09-29 22:01:34 UTC


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2020:4031 0 None None None 2020-09-29 20:44:00 UTC
Red Hat Product Errata RHSA-2020:4647 0 None None None 2020-11-04 02:39:03 UTC

Description Guilherme de Almeida Suckevicz 2020-06-04 18:11:15 UTC
In FreeRDP before 2.1.0, there is an out-of-bounds read in cliprdr_read_format_list. Clipboard format data read (by client or server) might read data out-of-bounds. This has been fixed in 2.1.0.

Reference:
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2j4w-v45m-95hf

Upstream commit:
https://github.com/FreeRDP/FreeRDP/commit/b73143cf7ee5fe4cdabcbf56908aa15d8a883821

Comment 1 Guilherme de Almeida Suckevicz 2020-06-04 18:11:41 UTC
Created freerdp tracking bugs for this issue:

Affects: epel-6 [bug 1844164]
Affects: fedora-all [bug 1844163]


Created freerdp1.2 tracking bugs for this issue:

Affects: epel-7 [bug 1844165]
Affects: fedora-all [bug 1844162]

Comment 2 Todd Cullum 2020-06-05 00:20:28 UTC
Note that the flaw in the files reported for this CVE does not exist in any Red Hat Enterprise Linux version. However, the flaw exists instead in cliprdr_process_format_list() in client/cliprdr_main.c and cliprdr_server_receive_format_list() in server/cliprdr_main.c for FreeRDP-2.0.0-rc4. This version is shipped in Red Hat Enterprise Linux 8 and Red Hat Enterprise Linux 7. freerdp 1.0.2, as shipped in Red Hat Enterprise Linux 6 is significantly different and this flaw does not appear to exist there. The issue is that the code:

		while (dataLen)
		{
			Stream_Read_UINT32(s, formats[index].formatId); /* formatId (4 bytes) */
			dataLen -= 4;

			formats[index].formatName = NULL;

if dataLen is less than 4, an out-of-bounds read is possible.

Comment 4 Todd Cullum 2020-06-05 00:38:33 UTC
Mitigation:

To mitigate this flaw in vulnerable versions, clipboard support should be disabled for freerdp sessions.

Comment 5 errata-xmlrpc 2020-09-29 20:43:58 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 22:01:34 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-2020-11085

Comment 7 errata-xmlrpc 2020-11-04 02:39:01 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


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