The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
Low
PR
The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
Unchanged
S
An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
(The following advisory is also available in PDF format for download at:
http://www.cybsec.com/vuln/CYBSEC_Security_Advisory_HTTP_Response_Splitt
ing_in_SAP_WAS.pdf )
CYBSEC S.A.
www.cybsec.com
Advisory Name: HTTP Response Splitting in SAP WAS (Web Application
Server)
Vulnerability Class: HTTP Response Splitting
Release Date: 11/09/2005
Affected Applications:
* SAP WAS 6.10
* SAP WAS 6.20
* SAP WAS 6.40
* SAP WAS 7.00
Affected Platforms:
* Platform-Independent
Local / Remote: Remote
Severity: High
Author: Leandro Meiners.
Vendor Status:
* Confirmed, patch released.
Reference to Vulnerability Disclosure Policy:
http://www.cybsec.com/vulnerability_policy.pdf
Product Overview:
=================
SAP Web Application Server is an open standard-based platform for
developing, and implementing Web applications. SAP Web Application
Server is a crucial component of mySAP® Technology platform as it serves
as the underlying infrastructure for many SAP solutions (for example,
SAP Portal).
SAP WAS provides a development infrastructure on which to develop,
distribute, and execute platform-independent Web services and business
applications. SAP Web Application Server supports ABAP, Java, and Web
services.
The vulnerability discovered only applies to the BSP runtime of SAP WAS.
Vulnerability Description:
==========================
SAP Web Application Server was found to be vulnerable to HTTP Response
Splitting, in the parameter sap-exiturl. For further reference regarding
HTTP Response Splitting see the whitepaper "HTTP Response Splitting, Web
Cache Poisoning Attacks, and Related Topics" (available at:
http://www.packetstormsecurity.org/papers/general/whitepaper_httprespons
e.pdf)
Exploit (PoC):
==============
If the string "%0a%0dHeader:+Value" is passed (omitting the double
quotes) as the value for the parameter sap-exiturl the string "Header:
value" (without the double quotes) is considered as another HTTP header,
indicating the presence of the vulnerability.
Solutions:
==========
The solution, provided by SAP, is to disable support for the parameter
in older 6.10 releases as well as SP's in 6.20 prior to SP54. For new
6.20 and 7.00 releases the sap-exiturl parameter will be submitted to a
customer configured white-list. For further information see SAP Note
887322.
Vendor Response:
================
* 09/23/2005: Initial Vendor Contact.
* 09/27/2005: Technical details for the vulnerabilities sent to vendor.
* 10/14/2005: Solutions provided by vendor for all vulnerabilities.
* 11/09/2005: Coordinate release of advisory.
Contact Information:
====================
For more information regarding the vulnerability feel free to contact
the author at lmeiners<at>cybsec.com.
For more information regarding CYBSEC: www.cybsec.com
----------------------------
Leandro Meiners
CYBSEC S.A. Security Systems
E-mail: lmeiners (at) cybsec (dot) com [email concealed]
Tel/Fax: [54-11] 4382-1600
Web: http://www.cybsec.com
PGP-Key: http://pgp.mit.edu:11371/pks/lookup?search=lmeiners&op=index