Remote Stack Buffer Overflow in Firebird SQL Server [CORE4058]

[firebird-automations]

Submitted by: Spencer McIntyre (zerosteiner)

Attachments:
bof.py

The FirebirdSQL server is vulnerable to a stack buffer overflow that can be
triggered when an unauthenticated user sends a specially crafted packet. The
result can lead to remote code execution as the user which runs the FirebirdSQL
server.

Proof of Concept and technical details:
https://gist.github.com/zeroSteiner/85daef257831d904479c

Commits: 63ad0f2 af11f55

====== Test Details ======

Bug was fixed on 2.5.5.26952.
On 2.5.2.26540, 2.5.3.26780 and 2.5.4.26856 following lines appear in firebird.log after execution of this test:

   \*\*\* DUMP \*\*\*
   Tag=\-1 Offset=18 Length=34 Eof=0
   Clump 5 at offset 0: AAAABBBBCCCCDDDD
   Fatal exception during clumplet dump: Invalid clumplet buffer structure: buffer end before end of clumplet \- clumplet too long
   Plain dump starting with offset 18: <05\><15\>localhost\.loca

===

[firebird-automations]

Modified by: @dyemanov

assignee: Alexander Peshkov [ alexpeshkoff ]

[firebird-automations]

Commented by: @AlexPeshkoff

Attachned python script to reproduce

[firebird-automations]

Modified by: @AlexPeshkoff

Attachment: http://bof.py [ 12292 ]

[firebird-automations]

Commented by: @AlexPeshkoff

A reason is a bug when extracting a group number from the CNCT info, sent by client. Size of received data was not checked. Bug exists from the first most days of firebird.

The main irony here is that this group info was never used later in the code, and therefore was cleaned up in the trunk. I.e. trunk does not require fixing.

[firebird-automations]

Modified by: @AlexPeshkoff

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 2.5.3 [ 10461 ]

Fix Version: 2.1.6 [ 10460 ]

[firebird-automations]

Commented by: Spencer McIntyre (zerosteiner)

I just tested against the latest build for 2.5.3 Windows 32-bit. Specifically I tested the classic, super and superclassic versions from this http://web.firebirdsql.org/download/snapshot_builds/win/2.5/Firebird-2.5.3.26618-0_Win32.zip and they were still vulnerable except for the classic version.

Could you please provide me a revision number for when this issue was fixed?

[firebird-automations]

Commented by: Spencer McIntyre (zerosteiner)

I just heard back from MITRE who has reserved CVE-2013-2492 to identify this vulnerability.

[firebird-automations]

Commented by: @dyemanov

The fixed snapshot builds will be available today, build numbers are 26623 for v2.5 and 18514 for v2.1.

[firebird-automations]

Modified by: @dyemanov

security: Developers [ 10012 ] =>

[firebird-automations]

Modified by: @dyemanov

Fix Version: 2.1.5 Update 1 [ 10522 ]

Fix Version: 2.5.2 Update 1 [ 10521 ]

[firebird-automations]

Modified by: @pcisar

status: Resolved [ 5 ] => Closed [ 6 ]

[firebird-automations]

Modified by: @pavel-zotov

status: Closed [ 6 ] => Closed [ 6 ]

QA Status: No test

[firebird-automations]

Modified by: @pavel-zotov

status: Closed [ 6 ] => Closed [ 6 ]

QA Status: No test => Done successfully

Test Details: Bug was fixed on 2.5.5.26952.
On 2.5.2.26540, 2.5.3.26780 and 2.5.4.26856 following lines appear in firebird.log after execution of this test:

   \*\*\* DUMP \*\*\*
   Tag=\-1 Offset=18 Length=34 Eof=0
   Clump 5 at offset 0: AAAABBBBCCCCDDDD
   Fatal exception during clumplet dump: Invalid clumplet buffer structure: buffer end before end of clumplet \- clumplet too long
   Plain dump starting with offset 18: <05\><15\>localhost\.loca

===