Bug 1655936 (CVE-2018-19626)

Summary:	CVE-2018-19626 wireshark: DCOM dissector crash resulting in information leak
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	denis, huzaifas, lemenkov, mruprich, msehnout, phatina, rvokal
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	wireshark 2.6.5, wireshark 2.4.11	Doc Type:	If docs needed, set a value
Doc Text:	Missing initialization of buffer in DCOM dissector could allow Wireshark to crash when parsing a specially crafted pcap file. A remote attacker could cause a denial of service to Wireshark by injecting malicious packets into the network that are automatically processed. Moreover, the content of uninitialized stack memory is leaked to the local user via Wireshark, causing an information leak as secondary impact.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-07-12 13:06:18 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:	1655944, 1657211
Bug Blocks:	1655949

Description Andrej Nemec 2018-12-04 09:53:50 UTC

In Wireshark 2.6.0 to 2.6.4 and 2.4.0 to 2.4.10, the DCOM dissector could crash. This was addressed in epan/dissectors/packet-dcom.c by adding '\0' termination.

Upstream issue:

https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=15130

Upstream patch:

https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=c5a65115ebab55cfd5ce0a855c2256e01cab6449

External References:

https://www.wireshark.org/security/wnpa-sec-2018-52.html

Comment 1 Andrej Nemec 2018-12-04 10:01:15 UTC

Created wireshark tracking bugs for this issue:

Affects: fedora-all [bug 1655944]

Comment 2 Adam Mariš 2018-12-07 12:57:00 UTC

According to upstream bug:

https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=15130#c8

This issue affects also older versions since commit:

https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=ea0baf468e778706c40e2fb0337fc65cd3e27ea5

when packet-dcom.c was introduced. The problem seems to be that dissect_dcom_BSTR() can end before calling dcom_tvb_get_nwstringz0() where szStr is initialized, leaving it uninitialized. But such possibility was only introduced by commit:

https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=0c7eb4a4f4d351aa99adefb798eec90293aac131 (which means since wireshark 2.1.0)

Comment 3 Adam Mariš 2018-12-07 13:28:35 UTC

Statement:

This issue did not affect the versions of wireshark as shipped with Red Hat Enterprise Linux 5, 6 and 7.

Comment 5 Product Security DevOps Team 2019-07-12 13:06:18 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-2018-19626