Bug 1388388 (CVE-2016-8623) - CVE-2016-8623 curl: Use-after-free via shared cookies
Summary: CVE-2016-8623 curl: Use-after-free via shared cookies
Status: CLOSED ERRATA
Alias: CVE-2016-8623
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=low,public=20161102,reported=2...
Keywords: Security
Depends On: 1390896 1390894 1390895
Blocks: 1388393
TreeView+ depends on / blocked
 
Reported: 2016-10-25 08:36 UTC by Andrej Nemec
Modified: 2019-06-08 21:32 UTC (History)
34 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2019-06-08 03:01:05 UTC


Attachments (Terms of Use)
Upstream patch (6.45 KB, patch)
2016-10-25 10:16 UTC, Andrej Nemec
no flags Details | Diff


External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2018:2486 None None None 2018-08-16 16:08 UTC
Red Hat Product Errata RHSA-2018:3558 None None None 2018-11-13 08:33 UTC

Description Andrej Nemec 2016-10-25 08:36:50 UTC
libcurl explicitly allows users to share cookies between multiple easy handles
that are concurrently employed by different threads.

When cookies to be sent to a server are collected, the matching function
collects all cookies to send and the cookie lock is released immediately
afterwards. That funcion however only returns a list with *references* back to
the original strings for name, value, path and so on. Therefore, if another
thread quickly takes the lock and frees one of the original cookie structs
together with its strings, a use-after-free can occur and lead to information
disclosure. Another thread can also replace the contents of the cookies from
separate HTTP responses or API calls.

External References:

https://curl.haxx.se/docs/adv_20161102I.html

Comment 1 Andrej Nemec 2016-10-25 10:16 UTC
Created attachment 1213818 [details]
Upstream patch

Comment 2 Adam Mariš 2016-11-02 08:29:14 UTC
Created curl tracking bugs for this issue:

Affects: fedora-all [bug 1390894]

Comment 3 Adam Mariš 2016-11-02 08:29:29 UTC
Created mingw-curl tracking bugs for this issue:

Affects: fedora-all [bug 1390895]
Affects: epel-7 [bug 1390896]

Comment 4 Stefan Cornelius 2016-11-03 09:42:21 UTC
There are some barriers here: an application needs to use libcurl via the "easy API", has to threaded, and on top of that a racy condition has to be triggered, which is probably hard to influence from the outside/malicious servers. I currently don't think that this is a significant problem in a RHEL context.

Comment 7 errata-xmlrpc 2018-08-16 16:07:43 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 8 errata-xmlrpc 2018-11-13 08:33:42 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


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