Bug 996774 (CVE-2011-4718) - CVE-2011-4718 php: session fixation vulnerability allows remote hijacking of sessions
Summary: CVE-2011-4718 php: session fixation vulnerability allows remote hijacking of ...
Alias: CVE-2011-4718
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 998341
Blocks: Embargoed996775
TreeView+ depends on / blocked
Reported: 2013-08-13 22:43 UTC by Vincent Danen
Modified: 2021-02-17 07:25 UTC (History)
16 users (show)

Fixed In Version: php 5.5.2
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2015-04-09 08:20:55 UTC

Attachments (Terms of Use)

Description Vincent Danen 2013-08-13 22:43:59 UTC
Common Vulnerabilities and Exposures assigned an identifier CVE-2011-4718 to
the following vulnerability:

Name: CVE-2011-4718
URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-4718
Assigned: 20111209
Reference: https://bugs.php.net/bug.php?id=60491
Reference: https://wiki.php.net/rfc/strict_sessions
Reference: http://git.php.net/?p=php-src.git;a=commit;h=169b78eb79b0e080b67f9798708eb3771c6d0b2f
Reference: http://git.php.net/?p=php-src.git;a=commit;h=25e8fcc88fa20dc9d4c47184471003f436927cde

Session fixation vulnerability in the Sessions subsystem in PHP before
5.5.2 allows remote attackers to hijack web sessions by specifying a
session ID.

Comment 1 Vincent Danen 2013-08-13 22:47:34 UTC
These look like the relevant commits:

http://git.php.net/?p=php-src.git;a=commitdiff;h=25e8fcc88fa20dc9d4c47184471003f436927cde (Strict session)
http://git.php.net/?p=php-src.git;a=commitdiff;h=82b0e8be99065b61b622df21bbc7494d2fbca3cd (Strict session. Detect session id collision)
http://git.php.net/?p=php-src.git;a=commitdiff;h=b80d73ce154e7f740f9ada446f45dbcdac38a64b (fix crash, enable session_id and fix test)

These are not minor changes, however.

Comment 3 Huzaifa S. Sidhpurwala 2013-08-19 05:15:10 UTC
Created php tracking bugs for this issue:

Affects: fedora-all [bug 998341]

Comment 4 Huzaifa S. Sidhpurwala 2013-08-19 05:24:29 UTC
Upstream suggests that this flaw can be mitigated by making changes to userland code, as detailed in:


Comment 5 Huzaifa S. Sidhpurwala 2013-08-19 05:30:55 UTC
This patch has been applied to php-5.5.3 branch (not released yet). The patch is however pretty invasive and mitigation techniques exists as mentioned in comment #4. Therefore this patch will not be backported to the older versions of php and php53 as shipped with Red Hat Enterprise Linux 5 and 6.


This issue affects the version of php and php53 as shipped with Red Hat Enterprise Linux 5. This issue affects the version of php as shipped with Red Hat Enterprise Linux 6 and 7. The Red Hat Security Response Team has rated this issue as having moderate security impact. This issue is not currently planned to be addressed in future updates.  This issue may be mitigated with user code changes as noted in https://wiki.php.net/rfc/strict_sessions#current_solution

Comment 8 Fedora Update System 2013-08-24 00:05:20 UTC
php-5.5.3-1.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Angelo Alvarez 2013-09-03 20:50:41 UTC
Any ideas when the fix for this CVE will make it into the RHEL 5.9 repo?

Comment 10 Vincent Danen 2013-09-05 22:51:10 UTC
Hi, Angelo.  As noted in comment #5, the patch is very invasive so there are currently no plans to backport the patch.

Comment 11 William Brown 2013-09-25 01:57:10 UTC
Additionally, Will this be considered for EL6.5? Given el6 is still in Production 1, I think this should be added.

Comment 12 Vincent Danen 2013-09-27 20:00:44 UTC
Hi, William.  The same problem noted in comment #10 exists for RHEL6.  It largely depends on whether or not upstream (who are clearly the experts here) will port this to the still-supported 5.4 or not.

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