[Bug 1203718] New: CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Bug ID: 1203718
           Summary: CVE-2015-1803 libXfont: crash on invalid read in
                    bdfReadCharacters
           Product: Security Response
         Component: vulnerability
          Keywords: Security
          Severity: low
          Priority: low
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail],
                    [e-mail],
                    [e-mail]

If the bdf parser failed to parse the data for the bitmap for any character, it
would proceed with an invalid pointer to the bitmap data and later crash when
trying to read the bitmap from that pointer.

A local user could exploit this issue to crash the X.Org server.

Upstream advisory:

http://seclists.org/oss-sec/2015/q1/865

Upstream patch:

http://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=78c2e3d70d29698244f...

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Martin Prpic  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends On|                            |1203720

Referenced Bugs:

https://bugzilla.redhat.com/show_bug.cgi?id=1203720
[Bug 1203720] CVE-2015-1802 libXfont: missing range check in
bdfReadProperties [fedora-all]

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Comment #1 from Martin Prpic  ---

Created libXfont tracking bugs for this issue:

Affects: fedora-all [bug 1203720]

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Martin Prpic  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |1203722

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718
Bug 1203718 depends on bug 1203720, which changed state.

Bug 1203720 Summary: CVE-2015-1804 CVE-2015-1802 CVE-2015-1803 libXfont: various flaws [fedora-all]
https://bugzilla.redhat.com/show_bug.cgi?id=1203720

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ON_QA                       |CLOSED
         Resolution|---                         |ERRATA

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Comment #2 from Fedora Update System  ---
libXfont-1.5.1-1.fc21 has been pushed to the Fedora 21 stable repository.  If
problems still persist, please make note of it in this bug report.

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Taylor Frazier  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Doc Text *updated* by Stefan Cornelius  ---
A NULL pointer dereference flaw was discovered in the way libXfont processed certain Glyph Bitmap Distribution Format (BDF) fonts. A malicious, local user could exploit this issue to crash the X.Org server.

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Stefan Cornelius  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Whiteboard|impact=low,public=20150317, |impact=low,public=20150317,
                   |reported=20150318,source=in |reported=20150318,source=in
                   |ternet,cvss2=1.9/AV:L/AC:M/ |ternet,cvss2=1.9/AV:L/AC:M/
                   |Au:N/C:N/I:N/A:P,rhel-5/lib |Au:N/C:N/I:N/A:P,rhel-5/lib
                   |Xfont=affected,rhel-6/libXf |Xfont=affected,rhel-6/libXf
                   |ont=affected,rhel-7/libXfon |ont=affected,rhel-7/libXfon
                   |t=affected,fedora-all/libXf |t=affected,fedora-all/libXf
                   |ont=affected                |ont=affected,cwe=CWE-252->C
                   |                            |WE-391->CWE-476

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Doc Text *updated* by Martin Prpic  ---
A NULL pointer dereference flaw was discovered in the way libXfont processed certain Glyph Bitmap Distribution Format (BDF) fonts. A malicious, local user could use this flaw to crash the X.Org server.

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Stefan Cornelius  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends On|                            |1258892

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Stefan Cornelius  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends On|                            |1258893

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Stefan Cornelius  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends On|                            |1258894

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Stefan Cornelius  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends On|                            |1258895

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Comment #4 from errata-xmlrpc  ---
This issue has been addressed in the following products:

Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2015:1708 https://rhn.redhat.com/errata/RHSA-2015-1708.html

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

[e-mail] changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #5 from [e-mail] ---
Hi guys,

Does this problem CVE affect libXfont shipped with RHEL5?

Best regards,
Dapeng

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

Matt Goldman  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #6 from Matt Goldman  ---
Dapeng,

Yes, from the whiteboard RHEL 5 is affected:

rhel-5/libXfont=affected

However, RHEL 5 has entered Production Phase 3 as of January 31, 2014. As per
our errata policy:

"During the Production 3 Phase, Critical impact Security Advisories (RHSAs)
and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they
become available."
    Red Hat Enterprise Linux Life Cycle
    https://access.redhat.com/support/policy/updates/errata#Production_3_Phase

This means that Red Hat will not be addressing Low, Moderate, or Important
impact CVE's in relation to RHEL 5.

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Comment #7 from [e-mail] ---
Hi Matt,

Thank you for your comment.

So there is some possibility that this problem will be fixed in rhel5, right?

But we can not guarantee that.

[Bug 1203718] CVE-2015-1803 libXfont: crash on invalid read in bdfReadCharacters

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1203718

--- Comment #8 from Matt Goldman  ---
Dapeng,

Correct. Likely, this will not be fixed in RHEL 5.