Bug 1053903 (CVE-2014-0015) - CVE-2014-0015 curl: re-use of wrong HTTP NTLM connection in libcurl
Summary: CVE-2014-0015 curl: re-use of wrong HTTP NTLM connection in libcurl
Alias: CVE-2014-0015
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1059326 1059327 1097085 1097086
Blocks: 1053909
TreeView+ depends on / blocked
Reported: 2014-01-15 23:47 UTC by Vincent Danen
Modified: 2023-05-12 13:01 UTC (History)
3 users (show)

Fixed In Version: curl 7.35.0
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2016-10-24 13:11:58 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2014:0561 0 normal SHIPPED_LIVE Moderate: curl security and bug fix update 2014-05-27 20:25:18 UTC

Description Vincent Danen 2014-01-15 23:47:10 UTC
Daniel Stenberg reported the following vulnerability in cURL:

   libcurl can in some circumstances re-use the wrong connection when asked to
   do an NTLM-authenticated HTTP or HTTPS request.

   libcurl features a pool of recent connections so that subsequent requests
   can re-use an existing connection to avoid overhead.

   When re-using a connection a range of criterion must first be met. Due to a
   logical error in the code, a request that was issued by an application could
   wrongfully re-use an existing connection to the same server that was
   authenticated using different credentials. One underlying reason being that
   NTLM authenticates connections and not requests, contrary to how HTTP is
   designed to work and how other authentication methods work.

   An application that allows NTLM and another auth method (the bug only
   triggers if more than one auth method is asked for) to a server (that
   responds wanting NTLM) with user1:password1 and then does another operation
   to the same server with user2:password2 (when the previous connection was
   left alive) - the second request will re-use the same connection and since
   it'll then see that the NTLM negotiation is already made, it will just send
   the request over that connection thinking it uses 'user2' credentials when
   it is in fact still using the connection authenticated for user1...

   The set of auth methods to use is set with CURLOPT_HTTPAUTH.

   Two common auth defines in libcurl are CURLAUTH_ANY and CURLAUTH_ANYSAFE.
   Both of them ask for NTLM and other methods and can therefore trigger this

   Applications can disable libcurl's re-use of connections and thus mitigate
   this problem, by using one of the following libcurl options to alter how
   connections are or aren't re-used: CURLOPT_FRESH_CONNECT,

This will be corrected in upstream libcurl and curl 7.35.0.

Comment 1 Vincent Danen 2014-01-15 23:49:25 UTC

Red Hat would like to thank the cURL project for reporting this issue.  Upstream acknowledges Paras Sethia as the original reporter and Yehezkel Horowitz for discovering the security impact.

Comment 2 Vincent Danen 2014-01-15 23:55:11 UTC
This is corrected upstream:


Comment 4 Kamil Dudka 2014-01-29 10:59:03 UTC
fixed in curl-7.35.0-1.fc21

Comment 5 Vincent Danen 2014-01-29 16:19:36 UTC
This affects libcurl 7.10.6 to and including 7.34.0.  It is fixed in version 7.35.0.

External References:


Comment 7 Vincent Danen 2014-01-29 16:21:47 UTC
Created curl tracking bugs for this issue:

Affects: fedora-all [bug 1059327]

Comment 8 Fedora Update System 2014-02-03 02:46:49 UTC
curl-7.32.0-4.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2014-02-15 20:02:12 UTC
curl-7.29.0-13.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 Vincent Danen 2014-03-26 15:28:14 UTC

Avoid using HTTP NTLM in your application.  If you must use NTLM authentication, ensure that it is the only requested authentication method (use --ntlm specifically, do not use --anyauth or other authentication methods).

Comment 13 errata-xmlrpc 2014-05-27 16:26:45 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:0561 https://rhn.redhat.com/errata/RHSA-2014-0561.html

Comment 14 Huzaifa S. Sidhpurwala 2014-05-28 04:18:32 UTC

This issue affects the version of curl as shipped with Red Hat Enterprise Linux 5 and 7. The Red Hat Security Response Team has rated this issue as having Moderate security impact, a future update may address this flaw.

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