Published:2017/06/28  Last Updated:2017/07/05

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) (1.17.1) and earlier
【Updated on July 5, 2017】
This advisory was first published on June 26, 2017.  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 July 3, 2017, 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".

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

Apply Workaround
Be sure to check no malicious file exists in the same directory where the installer is placed.
For more details, refer to the information provided by the developer.

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.