Published:2019/02/28  Last Updated:2019/02/28

Windows 7 may insecurely load Dynamic Link Libraries


Windows 7 may insecurely load Dynamic Link Libraries.

Products Affected

  • Windows 7


In standard DLL files provided by Windows 7, there are some DLL files read from the same directory where the program resides when executing the program (CWE-427).

Microsoft states that the root cause of this vulnerability is "Application Directory (App Dir) DLL planting", thus there is no plan to release any security updates for Windows 7 to address this issue.

For details, refer to "Application Directory (App Dir) DLL planting" released by Microsoft.


If a specially crafted DLL file is located in the same directory as executable file, arbitrary code may be executed.


Upgrade to Windows 10
Upgrade to the latest Windows 10 from Windows 7 according to the information provided by the developer.

Apply Workaround
Applying the following workarounds may mitigate the impacts of this vulnerability.

  • Restrict the permission to write system directories only to an administrator, which is the Windows' initial configuration.
  • Operate an Windows PC with a standard user (non-administrator) account.  An administrator account should be used only when necessary.
  • Make sure there are no untrusted files in the directory where the application is installed.
  • If your organization uses shared directories to place applications for organizational operations, make sure that the shared directory is set read-only for non-administrative users.

Vendor Status

Vendor Status Last Update Vendor Notes
Microsoft Japan Co.,Ltd. Vulnerable 2019/02/28


  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

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)
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)


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


Takashi Yoshikawa of Mitsui Bussan Secure Directions, Inc. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2019-5921
JVN iPedia JVNDB-2019-000013