Published:2017/06/28  Last Updated:2018/01/09

JVN#79451345
Installer of Setup file of advance preparation for e-Tax software (WEB version) may insecurely load Dynamic Link Libraries

Overview

Installer of Setup file of advance preparation for e-Tax software (WEB version) provided by National Tax Agency may insecurely load Dinamic Link Libraries.

Products Affected

  • Setup file of advance preparation for e-Tax software (WEB version) all versions distributed on the NTA website prior to 2018 January 4
【Updated on 2017 July 5】
This advisory was first published on 2017 June 26.  At that point it was stated that the affected product was version 1.17.0, and updating to version 1.17.1 was the solution.  However on 2017 July 3, it was confirmed the fix for this vulnerability incorporated in version 1.17.1 was not complete and the reported vulnerability still exists.
Therefore, the description of  the affected versions was modified to "1.17.1 and earlier".

【Updated on 2018 January 9】
National Tax Agency released the update that contains a fix for this vulnerability on 2018 January 4.  Therefore, the description of the affected versions was modified to "Setup file of advance preparation for e-Tax software (WEB version) all versions distributed on the NTA website prior to 2018 January 4".
 

Description

Installer of Setup file of advance preparation for e-Tax software (WEB version) provided by National Tax Agency contains an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries.

Impact

Arbitrary code may be executed with the privilege of the user invoking the installer.

Solution

Use the latest installer for the first-time installation or for updating the application
Users who have downloaded and obtained "Setup file of advance preparation for e-Tax software (WEB version)" distributed on the NTA website prior to 2018 January 4, be sure to delete it.
When installing or updating "Setup file of advance preparation for e-Tax software (WEB version)", execute the installer by following the instructions below.

  • Download the latest "Setup file of advance preparation for e-Tax software (WEB version)" released on 2018 January 4 from the NTA website.
  • Check and see if there are no suspicious files in the folder where the installer resides before executing the installer.
Users who already have installed "Setup file of advance preparation for e-Tax software (WEB version)" do not need to re-install the application, because this issue affects the installer only.

References

  1. Japan Vulnerability Notes JVNTA#91240916
    Insecure DLL Loading and Command Execution Issues on Many Windows Application Programs

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

CVSS v3 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Base Score: 7.8
Attack Vector(AV) Physical (P) Local (L) Adjacent (A) Network (N)
Attack Complexity(AC) High (H) Low (L)
Privileges Required(PR) High (H) Low (L) None (N)
User Interaction(UI) Required (R) None (N)
Scope(S) Unchanged (U) Changed (C)
Confidentiality Impact(C) None (N) Low (L) High (H)
Integrity Impact(I) None (N) Low (L) High (H)
Availability Impact(A) None (N) Low (L) High (H)
CVSS v2 AV:N/AC:M/Au:N/C:P/I:P/A:P
Base Score: 6.8
Access Vector(AV) Local (L) Adjacent Network (A) Network (N)
Access Complexity(AC) High (H) Medium (M) Low (L)
Authentication(Au) Multiple (M) Single (S) None (N)
Confidentiality Impact(C) None (N) Partial (P) Complete (C)
Integrity Impact(I) None (N) Partial (P) Complete (C)
Availability Impact(A) None (N) Partial (P) Complete (C)

Comment

This analysis assumes that the user is tricked into placing a malicious DLL file prepared by an attacker in a specific folder.

Credit

BlackWingCat of Pink Flying Whale reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Alert
JPCERT Reports
CERT Advisory
CPNI Advisory
TRnotes
CVE CVE-2017-2226
JVN iPedia JVNDB-2017-000145

Update History

2017/07/05
Information under [Product Affected] and [Solution] was modified.
2018/01/09
Information under [Product Affected] and [Solution] was modified, and a link under [Vendor Information] was added.