Advisory Details

January 29th, 2019

(0Day) Wecon LeviStudioU addresslib PLC Type Heap-based Buffer Overflow Remote Code Execution Vulnerability

ZDI-19-150
ZDI-CAN-6811

CVE ID CVE-2019-6539
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 LeviStudio
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 UMP files. When parsing the PLC element, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of Administrator.

ADDITIONAL DETAILS

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

07/12/18 – ZDI provided the reports to ICS-CERT
08/16/18 – ICS-CERT provided an ICS-VU#
11/15/18 – ZDI requested any update from ICS-CERT
11/26/18 – ZDI requested any update from ICS-CERT
12/07/18 – ZDI requested any update from ICS-CERT
01/09/19 – ZDI advised ICS-CERT of the intention to 0-day publish
01/25/19 – ZDI telephoned ICS-CERT to discuss status and 0-day publish

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


DISCLOSURE TIMELINE
  • 2018-07-25 - Vulnerability reported to vendor
  • 2019-01-29 - Coordinated public release of advisory
  • 2019-05-30 - Advisory Updated
CREDIT Ziad Badawi of Trend Micro Zero Day Initiative
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