Attacker Value
High
(1 user assessed)
Exploitability
Very High
(1 user assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
1

CVE-2020-13162

Disclosure Date: June 16, 2020
Add MITRE ATT&CK tactics and techniques that apply to this CVE.
Privilege Escalation
Techniques
Validation
Validated
Validated

Description

A time-of-check time-of-use vulnerability in PulseSecureService.exe in Pulse Secure Client versions prior to 9.1.6 down to 5.3 R70 for Windows (which runs as NT AUTHORITY/SYSTEM) allows unprivileged users to run a Microsoft Installer executable with elevated privileges.

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2
Ratings
Technical Analysis

PulseSecure version prior to 9.1.6 can be manually triggered to download and install an update. When this process is started, PulseSecure downloads the legitimate msi update file from the internet, verifies that the msi file is correct, then launches the Windows tool msiexec.exe to run the msi that was downloaded. By placing an oplock on the msiexec.exe file, an attacker can hold open the time between the file is verified and when it is run so that they can replace the downloaded msi after the verification takes place, but before the execution starts.

CVSS V3 Severity and Metrics
Base Score:
7.0 High
Impact Score:
5.9
Exploitability Score:
1
Vector:
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
High
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • pulsesecure

Products

  • pulse secure desktop client 5.3,
  • pulse secure desktop client 9.0,
  • pulse secure desktop client 9.1,
  • pulse secure installer service 8.3,
  • pulse secure installer service 9.1
Technical Analysis