Bug 1388390 (CVE-2016-8624)

Summary: CVE-2016-8624 curl: Invalid URL parsing with '#'
Product: [Other] Security Response Reporter: Andrej Nemec <anemec>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bmcclain, bodavis, cfergeau, csutherl, dbhole, dblechte, eedri, erik-fedora, gzaronik, hhorak, jclere, jorton, kanderso, kdudka, lgao, lsurette, luhliari, mbabacek, mgoldboi, michal.skrivanek, mike, mturk, myarboro, omajid, paul, rh-spice-bugs, rwagner, security-response-team, sherold, slawomir, srevivo, twalsh, weli, ykaul
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: curl 7.51.0 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2019-06-08 03:01:08 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: 1390894, 1390895, 1390896    
Bug Blocks: 1388393    
Attachments:
Description Flags
Upstream patch kdudka: review-

Description Andrej Nemec 2016-10-25 08:39:13 UTC 
curl doesn't parse the authority component of the URL correctly when the host
name part ends with a '#' character, and could instead be tricked into
connecting to a different host. This may have security implications if you for
example use an URL parser that follows the RFC to check for allowed domains
before using curl to request them.

Passing in `http://example.com#@evil.com/x.txt` would wrongly make curl send a
request to evil.com while your browser would connect to example.com given the
same URL.

The problem exists for most protocol schemes.

External References:

https://curl.haxx.se/docs/adv_20161102J.html
Comment 1 Andrej Nemec 2016-10-25 10:17:06 UTC 
Created attachment 1213819 [details]
Upstream patch
Comment 2 Adam Mariš 2016-11-02 08:29:42 UTC 
Created curl tracking bugs for this issue:

Affects: fedora-all [bug 1390894]
Comment 3 Adam Mariš 2016-11-02 08:29:57 UTC 
Created mingw-curl tracking bugs for this issue:

Affects: fedora-all [bug 1390895]
Affects: epel-7 [bug 1390896]
Comment 4 Kamil Dudka 2016-11-04 15:15:47 UTC 
Comment on attachment 1213819 [details]
Upstream patch

The patch seems to cause an unintended change in behavior:

https://curl.haxx.se/mail/lib-2016-11/0059.html
Comment 5 Kamil Dudka 2016-11-07 09:36:47 UTC 
Upstream considers the current behavior correct:

https://curl.haxx.se/mail/lib-2016-11/0084.html

... and wants to check file:// URLs stricter to provide better diagnostic messages in case the syntax is misused (namely allow to use only "localhost" or an empty string as the <host> part of the URL).

However, we need to make sure to keep the current (though undocumented) behavior of file://FILE_FROM_CURRENT_DIR unchanged while backporting the security fix for RHEL-6 and RHEL-7.
Comment 8 errata-xmlrpc 2018-08-16 16:07:45 UTC 
This issue has been addressed in the following products:

  Red Hat JBoss Core Services

Via RHSA-2018:2486 https://access.redhat.com/errata/RHSA-2018:2486
Comment 9 errata-xmlrpc 2018-11-13 08:33:46 UTC 
This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 7
  Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS

Via RHSA-2018:3558 https://access.redhat.com/errata/RHSA-2018:3558