Bug 1960343 (CVE-2021-32920)

Summary:	CVE-2021-32920 prosody: DoS via repeated TLS renegotiation causing excessive CPU consumption
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	jkaluza, redhat-bugzilla
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-05-13 20:33:48 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:	1960344, 1960357
Bug Blocks:

Description Guilherme de Almeida Suckevicz 2021-05-13 17:14:09 UTC

It was discovered that Prosody does not disable SSL/TLS renegotiation, even though this is not used in XMPP. A malicious client may flood a connection with renegotiation requests to consume excessive CPU resources on the server.
Support for disabling renegotiation depends on OpenSSL 1.1.1+ and LuaSec 0.7+.

The default configuration is susceptible to this issue.

Reference:
https://prosody.im/security/advisory_20210512/

Comment 1 Guilherme de Almeida Suckevicz 2021-05-13 17:14:23 UTC

Created prosody tracking bugs for this issue:

Affects: fedora-all [bug 1960344]

Comment 2 Robert Scheck 2021-05-13 17:15:23 UTC

Well, this also affects epel-all

Comment 3 Guilherme de Almeida Suckevicz 2021-05-13 17:22:30 UTC

Created prosody tracking bugs for this issue:

Affects: epel-all [bug 1960357]

Comment 4 Product Security DevOps Team 2021-05-13 20:33:48 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.