Bug 1970489 (CVE-2021-3595)

Summary:	CVE-2021-3595 QEMU: slirp: invalid pointer initialization may lead to information disclosure (tftp)
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	berrange, cfergeau, dbecker, jen, jferlan, jjoyce, jmaloy, jnovy, jschluet, knoel, lhh, lpeer, marcandre.lureau, mburns, mkenneth, mrezanin, mst, ondrejj, pbonzini, philmd, ribarry, rjones, sclewis, security-response-team, slinaber, virt-maint, virt-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libslirp 4.6.0	Doc Type:	If docs needed, set a value
Doc Text:	An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-11-09 23:21:37 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:	1970841, 1970843, 1970844, 1970845, 1970846, 1970847, 1970849, 1970850, 1972241, 1972242, 1972243
Bug Blocks:	1969478, 1970557

Description Mauro Matteo Cascella 2021-06-10 14:54:24 UTC

An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The function tftp_input() handles requests for the tftp protocol from the guest. While processing a udp packet that is smaller than the size of the tftp_t structure it uses memory from outside the working mbuf buffer. This issue may lead to out of bound read access or indirect memory disclosure to the guest.

Upstream commits:
https://gitlab.freedesktop.org/slirp/libslirp/-/commit/93e645e7
https://gitlab.freedesktop.org/slirp/libslirp/-/commit/3f179481
https://gitlab.freedesktop.org/slirp/libslirp/-/commit/990163cf

Comment 5 Mauro Matteo Cascella 2021-06-15 13:50:39 UTC

Created libslirp tracking bugs for this issue:

Affects: epel-all [bug 1972242]
Affects: fedora-all [bug 1972243]


Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1972241]

Comment 6 errata-xmlrpc 2021-11-09 17:40:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4191 https://access.redhat.com/errata/RHSA-2021:4191

Comment 7 Product Security DevOps Team 2021-11-09 23:21:34 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-2021-3595