Bug 1980260 (CVE-2020-36400)

Summary:	CVE-2020-36400 zeromq: heap-based buffer overflow in zmq::tcp_read
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	amctagga, andrewniemants, anharris, bniver, cfeist, dbecker, denis.arnaud_fedora, extras-orphan, flucifre, gmeno, hvyas, jjoyce, jschluet, lhh, lpeer, mbenjamin, mburns, mhackett, sclewis, slinaber, sostapov, tomspur, vereddy
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	zeromq 4.3.3	Doc Type:	If docs needed, set a value
Doc Text:	A flaw has been identified in zeromq. A heap-based buffer overflow is possible in zmq::tcp_read by resizing a fixed static allocator. The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-07-09 22:40:20 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:	1980261, 1980262, 1980263
Bug Blocks:	1980264

Description Marian Rehak 2021-07-08 08:26:38 UTC

ZeroMQ libzmq 4.3.3 has a heap-based buffer overflow in zmq::tcp_read by resizing a fixed static allocator, a different vulnerability than CVE-2021-20235.

Upstream Reference:

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26042

Upstream fix:

https://github.com/zeromq/libzmq/commit/397ac80850bf8d010fae23dd215db0ee2c677306

Comment 1 Marian Rehak 2021-07-08 08:27:48 UTC

Created zeromq tracking bugs for this issue:

Affects: epel-7 [bug 1980261]
Affects: openstack-rdo [bug 1980263]


Created zeromq3 tracking bugs for this issue:

Affects: epel-7 [bug 1980262]

Comment 2 Todd Cullum 2021-07-08 17:13:28 UTC

Flaw summary:

The c_single_allocator class in src/decoder_allocators.hpp of libzmq has a resize method which attempts to resize the static allocator when it should not (since it's a fixed buffer by design).

Comment 4 Product Security DevOps Team 2021-07-09 22:40:20 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-2020-36400