Bug 232241

Summary: CVE-2007-0720 Incomplete SSL negotiation prevents other clients from connecting to CUPS server
Product: Red Hat Enterprise Linux 5 Reporter: Lubomir Kundrak <lkundrak>
Component: cupsAssignee: Tim Waugh <twaugh>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: 5.0CC: ebenes, k.georgiou
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
URL: http://lists.apple.com/archives/security-announce/2007/Mar/msg00002.html
Whiteboard: impact=moderate,source=cve,reported=20070314,public=20061113
Fixed In Version: RHSA-2007-0123 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-04-16 11:51:41 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:    
Bug Blocks: 232242, 232243    
Attachments:
Description Flags
CVE-2007-0720 reproducer that uses dribbling to DoS even a patched version none

Description Lubomir Kundrak 2007-03-14 15:26:48 UTC 
Description of problem:

CUPS doesn't use separate workers for connections. During SSL
negotiation it does not accept new connections from anyone so
any user can DoS the server with unfinished negotiation.

Version-Release number of selected component (if applicable):

Both 1.2 <= 1.2.7 and 1.1 are affected.
I was able to reproduce on RHEL4, RHEL5.
FC6 (1.2.7) is already fixed.

How reproducible:

SSL support needs to be enabled. Default in 1.2.

Steps to Reproduce:
1. Launch the attached reproducer (eventually modify appropriately)
2. Let it run for at least 10 secs (to ensure that the server is not patched)
3. Attempt another connection to the CUPS server.
  
Actual results:

Hang.

Additional info:

The relevant fix:
http://www.cups.org/articles.php?L429+I10+T+P1+Q (r6110, r6081, r6079)
Comment 4 Lubomir Kundrak 2007-03-15 14:25:16 UTC 
*** Bug 232242 has been marked as a duplicate of this bug. ***
Comment 12 Red Hat Bugzilla 2007-04-16 11:51:41 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2007-0123.html
Comment 13 Lubomir Kundrak 2007-04-16 13:31:34 UTC 
Comment on attachment 151009 [details]
CVE-2007-0720 reproducer that uses dribbling to DoS even a patched version

CUPS server should _NOT_ be made publically accessible from untrusted networks.
Due to the design of the server it is still vulnerable to dribbling attacks as
demonstrated by the attached reproducer. This should not be a problem at all,
there is no practical need to override local-only default and enable access to
the print server from the Internet.