Vulnerability Database

325,773

Total vulnerabilities in the database

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.

  • Published: Jul 19, 2021
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-20110
  • Severity: Critical
  • Exploit:

CVSS v3:

  • Severity: Critical
  • Score: 9.8
  • AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v2:

  • Severity: High
  • Score: 10
  • AV:N/AC:L/Au:N/C:C/I:C/A:C

CWEs:

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.