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SAP Sybase Adaptive Server Enterprise vulnerable to XML injection

Vulnerability Note VU#303900

Original Release Date: 2013-10-17 | Last Revised: 2013-12-05

Overview

SAP Sybase Adaptive Server Enterprise Version 15.7 ESD 2 and possibly earlier versions contains an XML injection vulnerability (CWE-91).

Description

CWE-611: Improper Restriction of XML External Entity Reference ('XXE')

SAP Sybase Adaptive Server Enterprise (ASE) Version 15.7 ESD 2 contains an XML injection vulnerability, which can lead to information exposure. This is due to the expanded use of XML External Entity (XXE) Processing. The XMLParse procedure is vulnerable to attack. Using a specially crafted SQL request, an authenticated attacker may be able to read files with the permissions of the user running the ASE application.

For example, the attacker can read the /etc/passwd file of the server using the following SQL query:
SELECT xmlextract('/', xmlparse('<?xml version="1.0" standalone="yes"?><!DOCTYPE content [ <!ENTITY abc SYSTEM "/etc/passwd">]><content>&abc;</content>'))

Impact

An authenticated attacker may be able to use the vulnerabilities to read user credentials. This may be used to obtain unauthorized administrative or privileged access to the system.

Solution

Apply an Update
SAP has released a patch on the Sybase downloads page. If an update cannot be applied, please consider the following workaround.

Disable XXE
By disabling the external general entities feature of the SAXParserFactory used to parse the XML within Java code, the attacker cannot successfully make these requests. More details can be found on the OWASP XML External Entity (XXE) Processing page.

Vendor Information

303900
 
Affected   Unknown   Unaffected

SAP

Notified:  January 08, 2013 Updated:  October 15, 2013

Status

  Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.


CVSS Metrics

Group Score Vector
Base 2.3 AV:A/AC:M/Au:S/C:P/I:N/A:N
Temporal 1.8 E:POC/RL:OF/RC:C
Environmental 1.4 CDP:ND/TD:M/CR:ND/IR:ND/AR:ND

References

Acknowledgements

Thanks to Igor Bulatenko for reporting this vulnerability.

This document was written by Adam Rauf.

Other Information

CVE IDs: CVE-2013-6025
Date Public: 2013-10-01
Date First Published: 2013-10-17
Date Last Updated: 2013-12-05 22:06 UTC
Document Revision: 30

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