Bug 645672 (CVE-2010-3856) - CVE-2010-3856 glibc: ld.so arbitrary DSO loading via LD_AUDIT in setuid/setgid programs
Summary: CVE-2010-3856 glibc: ld.so arbitrary DSO loading via LD_AUDIT in setuid/setgi...
Alias: CVE-2010-3856
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 645677 645678 645679 645680 645875
TreeView+ depends on / blocked
Reported: 2010-10-22 08:28 UTC by Petr Matousek
Modified: 2023-05-11 15:26 UTC (History)
15 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2010-11-11 08:12:40 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2010:0793 0 normal SHIPPED_LIVE Important: glibc security update 2010-10-25 18:54:26 UTC
Red Hat Product Errata RHSA-2010:0872 0 normal SHIPPED_LIVE Important: glibc security and bug fix update 2010-11-10 12:10:56 UTC

Description Petr Matousek 2010-10-22 08:28:34 UTC
Tavis Ormandy pointed out that glibc does not properly sanitize DSOs that
are loaded using LD_AUDIT facility. Tavis quoted:

  In order to be preloaded during the execution of a privileged program, a
  library must be setuid and in the trusted library search path. This is a
  reasonable design, in order to be loaded a system administrator must brand
  a library as safe before it will be loaded across privilege boundaries.

  This allows developers who design their programs to operate safely while
  running as setuid are able to do so. The same conditions do not apply to
  LD_AUDIT, which will load an arbitrary DSOs, regardless of whether it
  has been designed to operate safely or not.

Tavis found out that by exploiting unsafely designed DSO constructors in
trusted directories it is possible to achieve privilege escalation.


Red Hat would like to thank Ben Hawkes and Tavis Ormandy for reporting this issue.

Comment 12 Petr Matousek 2010-10-22 17:02:38 UTC


Comment 13 Petr Matousek 2010-10-22 18:05:31 UTC
Created glibc tracking bugs for this issue

Affects: fedora-all [bug 645875]

Comment 14 Roberto Yokota 2010-10-22 18:07:56 UTC
Andreas Patch:



Roberto Yokota

Comment 15 Petr Matousek 2010-10-23 09:40:32 UTC
This issue did not affect the versions of glibc package as shipped with Red Hat Enterprise Linux 3 and 4 as these do not implement Auditing API for the dynamic linker.

Comment 18 errata-xmlrpc 2010-10-25 18:54:32 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2010:0793 https://rhn.redhat.com/errata/RHSA-2010-0793.html

Comment 19 errata-xmlrpc 2010-11-10 18:57:35 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2010:0872 https://rhn.redhat.com/errata/RHSA-2010-0872.html

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