Bug 446902 (CVE-2008-2363)

Summary: CVE-2008-2363 pan: heap overflow caused by large *.nzb files
Product: [Other] Security Response Reporter: Pavel Polischouk <pavel.polischouk>
Component: vulnerabilityAssignee: Alexander Dalloz <alex>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: low    
Version: unspecifiedCC: mpeters
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2012-05-24 21:37:28 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: 449333, 449334, 449335    
Bug Blocks:    
Attachments:
Description Flags
Tasks.nzb causing corrupted double-linked list abort from glibc
none
Glibc-generated stack trace from abort
none
Tasks.nzb causing pan to segfault
none
Stack trace from segfault
none
Tasks.nzb causing assertion in pan.
none
Stack trace from assertion
none
Fix the assertion in PAN due to sorting of an array containing redundant elements none

Description Pavel Polischouk 2008-05-16 16:01:51 UTC
Description of problem:


Version-Release number of selected component (if applicable):
pan-0.132-2.fc8.x86_64

How reproducible:
Always

Steps to Reproduce:
  Start pan from the command line
  
Actual results:

pan: parts.cc:244: void pan::Parts::set_parts(const pan::PartBatch&): Assertion
`pch == part_mid_buf + part_mid_buf_len' failed.
Aborted


Expected results:

PAN starts

Additional info:

Comment 1 Pavel Polischouk 2008-05-21 18:17:36 UTC
Created attachment 306290 [details]
Tasks.nzb causing corrupted double-linked list abort from glibc

Comment 2 Pavel Polischouk 2008-05-21 18:20:40 UTC
Debugged the problem further. It happens when trying to load a huge tasks.nzb
(around 95000 lines). When the file is split into two parts by copying and
removing extra <file>...</file> sections, each part loads successfully.
This most likely means state corruption in nzb parser by certain input.

Attaching the bad nzb files that cause: assertion, segmentation fault, or abort
inside glibc (double-linked list corruption detected).

Comment 3 Pavel Polischouk 2008-05-21 18:21:26 UTC
Created attachment 306292 [details]
Glibc-generated stack trace from abort

Comment 4 Pavel Polischouk 2008-05-21 18:24:08 UTC
Created attachment 306293 [details]
Tasks.nzb causing pan to segfault

Comment 5 Pavel Polischouk 2008-05-21 18:25:03 UTC
Created attachment 306294 [details]
Stack trace from segfault

Comment 6 Pavel Polischouk 2008-05-21 18:33:21 UTC
Created attachment 306296 [details]
Tasks.nzb causing assertion in pan.

Comment 7 Pavel Polischouk 2008-05-21 18:33:45 UTC
Created attachment 306297 [details]
Stack trace from assertion

Comment 8 Pavel Polischouk 2008-05-28 02:48:05 UTC
Found the root cause of the problem.

PartsBatch class has inconsistent storage for Parts. For each new batch, it does
not clear() the 'parts' variable, but only resize()s it if the new batch is
bigger (pan/data/parts.cc, lines 307 and 316). If the new batch is smaller than
the previous, extra entries are untouched.

The problem happens when pan attempts to sort the full vector
(pan/tasks/nzb.cc:128), thus possibly mixing the parts from the current batch
with the parts from the previous batches.

The solution is to clear() the 'parts' vector on each init(), then push_back()
the new parts in add_part, so the vector size always corresponds to the real
number of found parts.

Comment 9 Pavel Polischouk 2008-05-28 02:53:31 UTC
Created attachment 306880 [details]
Fix the assertion in PAN due to sorting of an array containing redundant elements

Added proper handling of PartBatch::parts vector.
Fixed allocation policy of Part::packed_mid element to re-allocate it every
time rather than trying to reuse a previous instance.

Signed-off by: pavelvp

Comment 10 Pavel Polischouk 2008-05-28 03:40:28 UTC
Note that when compiled with -O0 for ease of debugging, abort or segfault never
happen, assertion always happens instead.

Comment 11 Josh Bressers 2008-05-28 17:59:44 UTC
I'm assigning this issue CVE-2008-2363.  From the look of this, it looks like a
pretty generic heap overflow, which means we can't rule out arbitrary code
execution.

Comment 12 Pavel Polischouk 2008-05-31 10:01:27 UTC
Added dependency on bug 433970.
Building pan rpm with this assertion fix for F9 is impossible without
compilation fixes here: https://bugzilla.redhat.com/attachment.cgi?id=306299

Comment 13 Tomas Hoger 2008-06-02 08:40:57 UTC
Moving to Security Response product, creating tracking bugs.

Comment 15 Vincent Danen 2012-05-24 21:37:28 UTC
Current Pan in Fedora is 0.135+ and this was fixed in 0.133 (http://pan.rebelbase.com/download/releases/0.133/).