** Please note that this issue is confidential and no information should be disclosed until it is made public, see "Whiteboard" for a date ** libcurl Arbitrary File Access ============================= Project cURL Security Advisory, March 3rd 2009 http://curl.haxx.se/docs/security.html 1. VULNERABILITY When told to follow a "redirect" automatically, libcurl does not question the new target URL but will follow to any new URL that it understands. As libcurl supports FILE:// URLs, a rogue server can thus "trick" a libcurl-using application to read a local file instead of the remote one. This is a problem, for example, when the application is running on a server and is written to upload or to otherwise provide the transfered data to a user, to another server or to another application etc, as it can be used to expose local files it was not meant to. The problem can also be exploited for uploading, if the rogue server redirects the client to a local file and thus it would (over)write a local file instead of sending it to the server. libcurl compiled to support SCP can get tricked to get a file using embedded semicolons, which can lead to execution of commands on the given server. "Location: scp://name:passwd@host/a'``;date >/tmp/test``;'". Files on servers other than the one running libcurl are also accessible when credentials for those servers are stored in the .netrc file of the user running libcurl. This is most common for FTP servers, but can occur with any protocol supported by libcurl. Files on remote SSH servers are also accessible when when the user has an unencrypted SSH key. There is no known exploit at the time of this writing. The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2009-0037 to this issue. 2. AFFECTED VERSIONS Affected versions: curl and libcurl 5.11(!) to and including 7.19.3 Not affected versions: curl and libcurl 5.10 and earlier, 7.19.4 and later Also note that (lib)curl is used by many applications, and not always advertised as such. 3. THE SOLUTION libcurl 7.19.4 introduces a new option called CURLOPT_REDIR_PROTOCOLS, which applications can use to tell libcurl what target protocols automatic redirect followings are allowed to use. This will by default exclude FILE and SCP URLs. 4. RECOMMENDATIONS We suggest you take one of the following actions immediately, in order of preference: A - Upgrade to curl and libcurl 7.19.4 B - Apply the suitable patch and rebuild For current CVS HEAD: http://curl.haxx.se/CVE-2009-0037/curl-CVSHEAD-CVE-2009-0037.patch For curl 7.19.0: http://curl.haxx.se/CVE-2009-0037/curl-7.19.0-CVE-2009-0037.patch For curl 7.18.2: http://curl.haxx.se/CVE-2009-0037/curl-7.18.2-CVE-2009-0037.patch For curl 7.18.1: http://curl.haxx.se/CVE-2009-0037/curl-7.18.1-CVE-2009-0037.patch For curl 7.16.4: http://curl.haxx.se/CVE-2009-0037/curl-7.16.4-CVE-2009-0037.patch For curl 7.15.1: http://curl.haxx.se/CVE-2009-0037/curl-7.15.1-CVE-2009-0037.patch For curl 7.11.0: http://curl.haxx.se/CVE-2009-0037/curl-7.11.0-CVE-2009-0037.patch C - Disable automatic redirection following in your application and do the logic "manually" instead. 5. TIME LINE We were notified by David Kierznowski on Feb 6th, 2009. We discussed solutions and a first patch was written and tested on Feb 11th. Vendor-sec was contacted on Feb 12, 2009. We agreed on and coordinated the synchronous disclosure of this problem together with the curl 7.19.4 release. curl 7.19.4 was released on March 3 2009, just before this flaw was publicly disclosed. 6. CREDITS Reported to us by David Kierznowski. Thanks a lot! Daniel Fandrich researched the issue and helped with the fix. Michal Marek brought the SCP side of this issue and did a bunch of the patch backports. Daniel Stenberg wrote the primary patch and this advisory.
dragonheart/loki_val: Can you attach an ebuild applying the appropriate patch to this bug, so we can do prestable testing before the deadline here? Do not commit anything to CVS!
Created attachment 183256 [details] curl-7.19.3-r1.ebuild cvs ebuild patch for ${FILESDIR} is http://curl.haxx.se/CVE-2009-0037/curl-CVSHEAD-CVE-2009-0037.patch i'll change it back to a tarball for the release.
Arch Security Liaisons, please test the attached ebuild and report it stable on this bug. Target keywords : "alpha amd64 arm hppa ia64 ppc ppc64 s390 sh sparc x86" CC'ing current Liaisons: alpha : yoswink, armin76 amd64 : keytoaster, tester hppa : jer ppc : dertobi123 ppc64 : corsair sparc : fmccor x86 : maekke, armin76
sparc looks good with the patch (tests run with no failures).
amd64 seems fine: TESTDONE: 439 tests out of 439 reported OK: 100% TESTDONE: 526 tests were considered during 1040 seconds.
HPPA is OK.
Looks okay on alpha/arm/ia64/s390/sh/x86
This is public now, please commit the ebuild and mark it stable for the arches that approved. Thanks!
added 7.19.4
and remaining arches
ppc64 done
tested - comment 5 thanks Tobias
ppc stable, sorry for the delay.
GLSA request filed.
GLSA 200903-21, thanks everyone.
