Advisory Details

August 21st, 2019

(0Day) WECON LeviStudioU ShortMessage_Module SMtext Stack-based Buffer Overflow Remote Code Execution Vulnerability

ZDI-19-764
ZDI-CAN-8246

CVE ID
CVSS SCORE 7.8, (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
AFFECTED VENDORS WECON
AFFECTED PRODUCTS LeviStudioU
VULNERABILITY DETAILS

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of WECON LeviStudioU. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the handling of XML files. When parsing the ShortMessage SMtext element, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the Administrator.

ADDITIONAL DETAILS

This vulnerability is being disclosed publicly without a patch in accordance with the ZDI 120 day deadline.

03/06/19 - ZDI reported the vulnerability to ICS-CERT
03/12/19 - ICS-CERT acknowledged the report
06/24/19 - ICS-CERT contacted ZDI requesting the disclosure date
06/25/19- ZDI replied the case was due on 07/04/19
07/17/19 - ZDI contacted ICS-CERT requesting a status update and communicated the intention to 0-day
07/17/19 - ICS-CERT replied they had not received a response from the vendor
08/05/19 - ZDI notified ICS-CERT the cases will 0-day on 08/21/19

-- Mitigation:
Given the nature of the vulnerability the only salient mitigation strategy is to restrict interaction with the application.


DISCLOSURE TIMELINE
  • 2019-03-06 - Vulnerability reported to vendor
  • 2019-08-21 - Coordinated public release of advisory
  • 2019-08-21 - Advisory Updated
CREDIT Mat Powell of Trend Micro Zero Day Initiative
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