Bug 1296984 (CVE-2016-1232) - CVE-2016-1232 prosody: use of weak PRNG in generation of dialback secrets
Summary: CVE-2016-1232 prosody: use of weak PRNG in generation of dialback secrets
Status: NEW
Alias: CVE-2016-1232
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=moderate,public=20160108,repor...
Keywords: Security
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-01-08 15:44 UTC by Robert Scheck
Modified: 2019-06-08 20:55 UTC (History)
1 user (show)

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Description Robert Scheck 2016-01-08 15:44:46 UTC
It was discovered that Prosody's generation of the secret token for
server-to-server dialback authentication relied upon a weak random
number generator that was not cryptographically secure. This allows
an attacker to guess at probable values of the secret key. A successful
guess allows impersonation of the affected domain to other servers on
the network.

External References:

https://prosody.im/security/advisory_20160108-2/

Comment 1 Martin Prpič 2016-01-11 08:51:50 UTC
Affected configurations
-----------------------

Configurations with mod_dialback loaded (default configuration) are
affected.

Servers with s2s_secure_auth = true will not be susceptible to incoming
attempts to spoof other domains on the network. However if mod_dialback
is loaded, a server's domain's may still be spoofed by an attacker in
connections to other servers.

Not affected are configurations with a strong custom dialback_secret set
(though periodically regenerating the dialback_secret is still
advisable).

Temporary mitigation
--------------------

Set the 'dialback_secret' option in your configuration file to a long
random string.

A strong dialback_secret can be generated (for example) using the
command:

head -c 32 /dev/urandom | base64

Alternatively disable mod_dialback by adding it to your modules_disabled
option in your configuration file. In this case communication with
servers that only support dialback or have untrusted certificates will
not be possible.

Comment 2 Martin Prpič 2016-01-11 08:52:01 UTC
This has been fixed in:

prosody-0.9.9-1.fc24
prosody-0.9.9-1.fc22
prosody-0.9.9-1.el5
prosody-0.9.9-1.fc23
prosody-0.9.9-1.el7
prosody-0.9.9-1.el6

Comment 3 Fedora Update System 2016-01-20 21:55:54 UTC
prosody-0.9.9-2.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 4 Fedora Update System 2016-01-21 04:48:40 UTC
prosody-0.9.9-2.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2016-01-22 00:57:42 UTC
prosody-0.9.9-2.el6 has been pushed to the Fedora EPEL 6 stable repository. If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2016-01-26 15:42:21 UTC
prosody-0.9.9-2.el5 has been pushed to the Fedora EPEL 5 stable repository. If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2016-01-27 16:12:52 UTC
prosody-0.9.9-2.el7 has been pushed to the Fedora EPEL 7 stable repository. If problems still persist, please make note of it in this bug report.


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