CVE-2021-20110 Information

Description

Due to Manage Engine Asset Explorer Agent 1.0.34 not validating HTTPS certificates an attacker on the network can statically configure their IP address to match the Asset Explorer’s Server IP address. This will allow an attacker to send a NEWSCAN request to a listening agent on the network as well as receive the agent’s HTTP request verifying its authtoken. In httphandler.cpp the agent reaching out over HTTP is vulnerable to an Integer Overflow which can be turned into a Heap Overflow allowing for remote code execution as NT AUTHORITY/SYSTEM on the agent machine. The Integer Overflow occurs when receiving POST response from the Manage Engine server and the agent calling \HttpQueryInfoW\ in order to get the \Content-Length\ size from the incoming POST request. This size is taken but multiplied to a larger amount. If an attacker specifies a Content-Length size of 1073741823 or larger this integer arithmetic will wrap the value back around to smaller integer then calls ## CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

https://www.tenable.com/security/research/tra-2021-31

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8