CVE-2021-20110: Due to Manage Engine Asset Explorer Agent 1.0.34 not validating HTTPS certificates, an attacker on the network can statically configure their IP addre...

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 "calloc" with this size to allocate memory. The following API "InternetReadFile" will copy the POST data into this buffer, which will be too small for the contents, and cause heap overflow.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

7.38%

93.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-190

Affected Software

Vendor	Product	Versions
Zohocorp	Manageengine Assetexplorer	1.0.34

References

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

Timeline

Published: Jul 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20110?

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 "calloc" with this size to allocate memory. The following API "InternetReadFile" will copy the POST data into this buffer, which will be too small for the contents, and cause heap overflow.

How severe is CVE-2021-20110?

CVE-2021-20110 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 7.38% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20110?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.