Published:2017/07/14  Last Updated:2017/07/14

JVN#61502349
Self-Extracting Encrypted Files created by AttacheCase may insecurely load Dynamic Link Libraries

Overview

Self-extracting encrypted files created by AttacheCase may insecurely load Dynamic Link Libraries.

Products Affected

Self-extracting encrypted files created by the following software are affected:

  • AttacheCase ver.2.8.3.0 and earlier - CVE-2017-2271
  • AttacheCase ver.3.2.2.6 and earlier - CVE-2017-2272

Description

AttacheCase is an open source file encryption software provided by HiBARA Software. It can also create self-extracting encrypted files. Self-extracting encrypted files created by AttacheCase contain an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries (CWE-427).

Impact

Arbitrary code may be executed with the privilege of the user invoking a vulnerable self-extracting encrypted file.

Solution

Apply Workarounds

  • When invoking a self-extracting encrypted file, make sure no unrelated files exist within the same directory. It is best to copy the installer into a newly created directory and invoke it from that directory
  • Make sure no untrusted files exist within the directory where the self-extracting encrypted file is invoked.
  • If you have some shared directory within your organization to place self-extracting encrypted files, make sure that this shared directory is read-only for non-administrative users
  • Operate self-extracting encrypted files using a standard user (non-administrator) account. Administrator accounts should be used only when necessary.

Vendor Status

Vendor Status Last Update Vendor Notes
HiBARA Software Vulnerable 2017/07/14 HiBARA Software website

References

  1. Japan Vulnerability Note 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 in the same directory where a vulnerable encrypted files in self-executable format resides.

Credit

Eili Masami of Tachibana Lab. 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-2017-2271
CVE-2017-2272
JVN iPedia JVNDB-2017-000174