Bug 919549 (CVE-2013-2492)

Summary:	CVE-2013-2492 Firebird: CNCT info remote stack buffer overflow
Product:	[Other] Security Response	Reporter:	Kurt Seifried <kseifried>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED CURRENTRELEASE	QA Contact:
Severity:	urgent	Docs Contact:
Priority:	urgent
Version:	unspecified	CC:	carnil, jlieskov, makowski.fedora, rcvalle
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-04-01 16:18:13 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:	919551, 919552
Bug Blocks:

Description Kurt Seifried 2013-03-08 19:02:55 UTC

Spencer McIntyre reports:

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. 

Alexander Peshkov adds:

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. 

This is fixed in snapshot builds, build numbers are 26623 for v2.5 and 18514 
for v2.1. Fix available in upstream SVN repository for B2_5_Release branch
(revision 57728).

external references:
http://tracker.firebirdsql.org/browse/CORE-4058

Comment 1 Kurt Seifried 2013-03-08 19:05:48 UTC

Created firebird tracking bugs for this issue

Affects: epel-all [bug 919551]

Comment 2 Jan Lieskovsky 2013-03-15 14:12:31 UTC

Other references:
  https://gist.github.com/zeroSteiner/85daef257831d904479c
  https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/misc/fb_cnct_group.rb

Comment 3 Ramon de C Valle 2013-03-15 17:51:57 UTC

http://tracker.firebirdsql.org/browse/CORE-4058
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=702735#10

Comment 4 Ramon de C Valle 2013-03-15 17:53:36 UTC

Index: src/remote/inet.cpp
===================================================================
--- src/remote/inet.cpp	(revision 57727)
+++ src/remote/inet.cpp	(revision 57728)
@@ -1252,7 +1252,7 @@
 		case CNCT_group:
 			{
 				const size_t length = id.getClumpLength();
-				if (length != 0)
+				if (length <= sizeof(eff_gid) && length > 0)
 				{
 					eff_gid = 0;
 					memcpy(&eff_gid, id.getBytes(), length);

Comment 5 Fedora Update System 2013-03-20 21:36:28 UTC

firebird-2.5.2.26539.0-2.fc17 has been pushed to the Fedora 17 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2013-03-20 21:43:27 UTC

firebird-2.5.2.26539.0-2.fc18 has been pushed to the Fedora 18 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2013-03-26 16:41:55 UTC

firebird-2.5.2.26539.0-3.el6 has been pushed to the Fedora EPEL 6 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 8 Fedora Update System 2013-03-26 16:46:06 UTC

firebird-2.1.5.18496.0-4.el5 has been pushed to the Fedora EPEL 5 stable repository.  If problems still persist, please make note of it in this bug report.