[prev in list] [next in list] [prev in thread] [next in thread]
List: oss-security
Subject: [oss-security] socat security advisory 4 - CVE-2013-3571
From: Gerhard Rieger <gerhard () dest-unreach ! org>
Date: 2013-05-26 18:31:14
Message-ID: 51A254F2.2030506 () dest-unreach ! org
[Download RAW message or body]
Socat security advisory - FD leak
Overview
Under certain circumstances an FD leak occurs and can be misused for
denial of service attacks against socat running in server mode.
Vulnerability Id: CVE-2013-3571
Details
The issue occurs when a vulnerable version of socat is invoked with a
listen type address with option fork and one or more of the options
sourceport, lowport, range, or tcpwrap. When socat refuses a client
connection due to one of these address or port restrictions it does
shutdown() the socket but does not close() it, resulting in a file
descriptor leak in the listening process, visible with command lsof
and possibly resulting in error EMFILE "Too many open files".
Testcase
In one terminal run the server:
socat -d tcp-listen:10000,reuseaddr,fork,range=0.0.0.0/32 pipe
In a second terminal see which FDs are open, then connect (implicitely
using a forbidden address), and check if there is a new FD open, e.g.:
lsof -p $(pgrep socat)
socat /dev/null tcp:localhost:10000
lsof -p $(pgrep socat)
If the second lsof shows an additional FD as in the following line,
this socat version is vulnerable:
socat 17947 gerhard 4u sock 0,6 0t0 1145265 can't identify protocol
Workaround
Use IP filters in your OS or firewall.
Restart socat when it crashed.
Affected versions
1.2.0.0 - 1.7.2.1
2.0.0-b1 - 2.0.0-b5
Not affected or corrected versions
1.0.0.0 - 1.1.0.1
1.7.2.2 and later
2.0.0-b6 and later
Download
The updated sources can be downloaded from:
http://www.dest-unreach.org/socat/download/socat-1.7.2.2.tar.gz
http://www.dest-unreach.org/socat/download/socat-2.0.0-b6.tar.gz
Patch to 1.7.2.1:
http://www.dest-unreach.org/socat/download/socat-1.7.2.2.patch.gz
Patch to 2.0.0-b5:
http://www.dest-unreach.org/socat/download/socat-2.0.0-b6.patch.gz
Credits
Full credits to Catalin Mitrofan for finding and reporting this issue.
["signature.asc" (application/pgp-signature)]
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic