Vulnerability Note VU#303900

SAP Sybase Adaptive Server Enterprise vulnerable to XML injection

Original Release date: 17 Oct 2013 | Last revised: 05 Dec 2013

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 (Learn More)

VendorStatusDate NotifiedDate Updated
SAPAffected08 Jan 201315 Oct 2013
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

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

Credit

Thanks to Igor Bulatenko for reporting this vulnerability.

This document was written by Adam Rauf.

Other Information

  • CVE IDs: CVE-2013-6025
  • Date Public: 01 Oct 2013
  • Date First Published: 17 Oct 2013
  • Date Last Updated: 05 Dec 2013
  • Document Revision: 30

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