Vulnerability Database

325,773

Total vulnerabilities in the database

CVE-2021-42099

Zoho ManageEngine M365 Manager Plus before 4421 is vulnerable to file-upload remote code execution.

  • Published: Nov 30, 2021
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-42099
  • 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: 7.5
  • AV:N/AC:L/Au:N/C:P/I:P/A:P

CWEs:

Software From Fixed in
zohocorp / manageengine_m365_manager_plus build_4419 build_4419.x
zohocorp / manageengine_m365_manager_plus build_4418 build_4418.x
zohocorp / manageengine_m365_manager_plus build_4417 build_4417.x
zohocorp / manageengine_m365_manager_plus build_4416 build_4416.x
zohocorp / manageengine_m365_manager_plus build_4415 build_4415.x
zohocorp / manageengine_m365_manager_plus build_4414 build_4414.x
zohocorp / manageengine_m365_manager_plus build_4413 build_4413.x
zohocorp / manageengine_m365_manager_plus build_4412 build_4412.x
zohocorp / manageengine_m365_manager_plus build_4411 build_4411.x
zohocorp / manageengine_m365_manager_plus build_4410 build_4410.x
zohocorp / manageengine_m365_manager_plus build_4408 build_4408.x
zohocorp / manageengine_m365_manager_plus build_4407 build_4407.x
zohocorp / manageengine_m365_manager_plus build_4406 build_4406.x
zohocorp / manageengine_m365_manager_plus build_4403 build_4403.x
zohocorp / manageengine_m365_manager_plus build_4402 build_4402.x
zohocorp / manageengine_m365_manager_plus build_4401 build_4401.x
zohocorp / manageengine_m365_manager_plus build_4400 build_4400.x
zohocorp / manageengine_m365_manager_plus build_4336 build_4336.x
zohocorp / manageengine_m365_manager_plus build_4335 build_4335.x
zohocorp / manageengine_m365_manager_plus build_4334 build_4334.x
zohocorp / manageengine_m365_manager_plus build_4333 build_4333.x
zohocorp / manageengine_m365_manager_plus build_4332 build_4332.x
zohocorp / manageengine_m365_manager_plus build_4331 build_4331.x
zohocorp / manageengine_m365_manager_plus build_4330 build_4330.x
zohocorp / manageengine_m365_manager_plus build_4329 build_4329.x
zohocorp / manageengine_m365_manager_plus build_4328 build_4328.x
zohocorp / manageengine_m365_manager_plus build_4327 build_4327.x
zohocorp / manageengine_m365_manager_plus build_4325 build_4325.x
zohocorp / manageengine_m365_manager_plus build_4324 build_4324.x
zohocorp / manageengine_m365_manager_plus build_4322 build_4322.x
zohocorp / manageengine_m365_manager_plus build_4321 build_4321.x
zohocorp / manageengine_m365_manager_plus build_4320 build_4320.x
zohocorp / manageengine_m365_manager_plus build_4319 build_4319.x
zohocorp / manageengine_m365_manager_plus build_4318 build_4318.x
zohocorp / manageengine_m365_manager_plus build_4317 build_4317.x
zohocorp / manageengine_m365_manager_plus build_4316 build_4316.x
zohocorp / manageengine_m365_manager_plus build_4312 build_4312.x
zohocorp / manageengine_m365_manager_plus build_4311 build_4311.x
zohocorp / manageengine_m365_manager_plus build_4310 build_4310.x
zohocorp / manageengine_m365_manager_plus build_4309 build_4309.x
zohocorp / manageengine_m365_manager_plus build_4308 build_4308.x
zohocorp / manageengine_m365_manager_plus build_4306 build_4306.x
zohocorp / manageengine_m365_manager_plus build_4305 build_4305.x
zohocorp / manageengine_m365_manager_plus build_4304 build_4304.x
zohocorp / manageengine_m365_manager_plus build_4303 build_4303.x
zohocorp / manageengine_m365_manager_plus build_4302 build_4302.x
zohocorp / manageengine_m365_manager_plus build_4301 build_4301.x
zohocorp / manageengine_m365_manager_plus build_4300 build_4300.x
zohocorp / manageengine_m365_manager_plus build_4222 build_4222.x
zohocorp / manageengine_m365_manager_plus build_4221 build_4221.x
zohocorp / manageengine_m365_manager_plus build_4220 build_4220.x
zohocorp / manageengine_m365_manager_plus build_4219 build_4219.x
zohocorp / manageengine_m365_manager_plus build_4218 build_4218.x
zohocorp / manageengine_m365_manager_plus build_4217 build_4217.x
zohocorp / manageengine_m365_manager_plus build_4216 build_4216.x
zohocorp / manageengine_m365_manager_plus build_4215 build_4215.x
zohocorp / manageengine_m365_manager_plus build_4214 build_4214.x
zohocorp / manageengine_m365_manager_plus build_4213 build_4213.x
zohocorp / manageengine_m365_manager_plus build_4212 build_4212.x
zohocorp / manageengine_m365_manager_plus build_4211 build_4211.x
zohocorp / manageengine_m365_manager_plus build_4210 build_4210.x
zohocorp / manageengine_m365_manager_plus build_4209 build_4209.x
zohocorp / manageengine_m365_manager_plus build_4208 build_4208.x
zohocorp / manageengine_m365_manager_plus build_4207 build_4207.x
zohocorp / manageengine_m365_manager_plus build_4206 build_4206.x
zohocorp / manageengine_m365_manager_plus build_4205 build_4205.x
zohocorp / manageengine_m365_manager_plus build_4204 build_4204.x
zohocorp / manageengine_m365_manager_plus build_4203 build_4203.x
zohocorp / manageengine_m365_manager_plus build_4202 build_4202.x
zohocorp / manageengine_m365_manager_plus build_4201 build_4201.x
zohocorp / manageengine_m365_manager_plus build_4200 build_4200.x
zohocorp / manageengine_m365_manager_plus build_4119 build_4119.x
zohocorp / manageengine_m365_manager_plus build_4118 build_4118.x
zohocorp / manageengine_m365_manager_plus build_4117 build_4117.x
zohocorp / manageengine_m365_manager_plus build_4116 build_4116.x
zohocorp / manageengine_m365_manager_plus build_4115 build_4115.x
zohocorp / manageengine_m365_manager_plus build_4113 build_4113.x
zohocorp / manageengine_m365_manager_plus build_4112 build_4112.x
zohocorp / manageengine_m365_manager_plus build_4111 build_4111.x
zohocorp / manageengine_m365_manager_plus build_4110 build_4110.x
zohocorp / manageengine_m365_manager_plus build_4109 build_4109.x
zohocorp / manageengine_m365_manager_plus build_4108 build_4108.x
zohocorp / manageengine_m365_manager_plus build_4106 build_4106.x
zohocorp / manageengine_m365_manager_plus build_4105 build_4105.x
zohocorp / manageengine_m365_manager_plus build_4104 build_4104.x
zohocorp / manageengine_m365_manager_plus build_4103 build_4103.x
zohocorp / manageengine_m365_manager_plus build_4102 build_4102.x
zohocorp / manageengine_m365_manager_plus build_4101 build_4101.x
zohocorp / manageengine_m365_manager_plus build_4100 build_4100.x
zohocorp / manageengine_m365_manager_plus build_4014 build_4014.x
zohocorp / manageengine_m365_manager_plus build_4013 build_4013.x
zohocorp / manageengine_m365_manager_plus build_4012 build_4012.x
zohocorp / manageengine_m365_manager_plus build_4011 build_4011.x
zohocorp / manageengine_m365_manager_plus build_4010 build_4010.x
zohocorp / manageengine_m365_manager_plus build_4009 build_4009.x
zohocorp / manageengine_m365_manager_plus build_4008 build_4008.x
zohocorp / manageengine_m365_manager_plus build_4007 build_4007.x
zohocorp / manageengine_m365_manager_plus build_4005 build_4005.x
zohocorp / manageengine_m365_manager_plus build_4004 build_4004.x
zohocorp / manageengine_m365_manager_plus build_4003 build_4003.x
zohocorp / manageengine_m365_manager_plus build_4002 build_4002.x
zohocorp / manageengine_m365_manager_plus build_4001 build_4001.x
zohocorp / manageengine_m365_manager_plus build_4000 build_4000.x

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.