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: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: jkaluza, redhat-bugzilla
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Last Closed: 2021-05-13 20:33:48 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1960344, 1960357    
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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.


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.