Bug 1388388 (CVE-2016-8623)

Summary: CVE-2016-8623 curl: Use-after-free via shared cookies
Product: [Other] Security Response Reporter: Andrej Nemec <anemec>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: low Docs Contact:
Priority: low    
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 03:01:05 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 none

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 10:16:35 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