Bug 550346 (CVE-2009-4411) - CVE-2009-4411 acl: vulnerable to symlink attacks
Summary: CVE-2009-4411 acl: vulnerable to symlink attacks
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2009-4411
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: http://web.nvd.nist.gov/view/vuln/det...
Whiteboard:
Depends On: 488674 552665
Blocks:
TreeView+ depends on / blocked
 
Reported: 2009-12-24 16:20 UTC by Vincent Danen
Modified: 2021-11-12 20:03 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-08-22 15:47:45 UTC
Embargoed:


Attachments (Terms of Use)

Description Vincent Danen 2009-12-24 16:20:25 UTC
Common Vulnerabilities and Exposures assigned an identifier CVE-2009-4411 to
the following vulnerability:

Name: CVE-2009-4411
URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-4411
Assigned: 20091223
Reference: MLIST:[oss-security] 20091223 CVE request: acl 2.2.47 always follows symlinks
Reference: URL: http://www.openwall.com/lists/oss-security/2009/12/23/2
Reference: CONFIRM: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=499076
Reference: CONFIRM: http://git.savannah.gnu.org/cgit/acl.git/commit/?id=63451a0
Reference: CONFIRM: http://oss.sgi.com/bugzilla/show_bug.cgi?id=790
Reference: BID:37455
Reference: URL: http://www.securityfocus.com/bid/37455
Reference: SECUNIA:37907
Reference: URL: http://secunia.com/advisories/37907
Reference: XF:acl-setfacl-getfacl-symlink(55004)
Reference: URL: http://xforce.iss.net/xforce/xfdb/55004

The (1) setfacl and (2) getfacl commands in XFS acl 2.2.47, when
running in recursive (-R) mode, follow symbolic links even when the
--physical (aka -P) or -L option is specified, which might allow local
users to modify the ACL for arbitrary files or directories via a
symlink attack.

Comment 22 Vincent Danen 2010-01-19 16:07:45 UTC
This issue does not affect Red Hat Enterprise Linux 3, 4 or 5 because the -P and -L options work as documented.

While investigating this issue, it was discovered that the setfacl -R option (whhen used without the -P or -L options) did behave contrary to what the manpage documentation specified by following symlinks in sub-directories when setting ACLs, in Red Hat Enterprise Linux 3 and 4.

Due to this behaviour, changing how -R behaves would cause a regression of long-established behaviour in setfacl.  The Red Hat Security Response Team have rated this issue as having low impact, and any potential fix has the risk of introducing a regression to relied upon (albeit incorrect) behaviour.

A separate bug was created to track this issue for Red Hat Enterprise Linux 4.  A fix may appear in future updates released as part of scheduled updates, if approved by product management (see bug #556880).


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