Exploited CVEs / Zoho / CVE-2021-37415

CVE-2021-37415

Zoho ManageEngine ServiceDesk Authentication Bypass Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2021-12-15 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Zoho ManageEngine Security Advisories, linked below.

Risk summary

CriticalCISA KEV

9.8

CVSS v3 base

100%

EPSS exploit probability

Critical

Severity

2021-12-01

Added to KEV

2021-12-15 (past due)

CISA due date

Actively exploited Zoho ManageEngine ServiceDesk Plus (SDP) vulnerability, Critical severity, CVSS v3 9.8. Added to the CISA KEV catalog 2021-12-01.

Senserva AI read on CVE-2021-37415 CISA required action Official fix for CVE-2021-37415 Admin questions

Senserva AI Opinion for CVE-2021-37415

Zoho ManageEngine ServiceDesk Plus before build 11302 exposes REST API URLs that skip authentication entirely, a Critical (CVSS 9.8) bypass with a 100% EPSS score. Help desk platforms hold credentials, asset data, and tickets full of internal detail, which makes an unauthenticated door into one a rich prize. Confirmed exploitation put it on CISA's KEV list in December 2021.

Do this: Upgrade ServiceDesk Plus to build 11302 or later and audit API access logs for unauthenticated calls.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2021-37415

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2021-37415, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2021-37415.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2021-37415: Zoho ManageEngine ServiceDesk Authentication Bypass Vulnerability
- Affected: Zoho ManageEngine ServiceDesk Plus (SDP)
- Severity: Critical, CVSS v3 9.8; EPSS 30-day exploitation probability 100%
- Added to CISA KEV: 2021-12-01; federal remediation due 2021-12-15
- Ransomware-linked: no
- CISA required action: Apply updates per vendor instructions.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

The fix ships from the vendor: Zoho ManageEngine Security Advisories.

Do this now: Federal remediation deadline 2021-12-15; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 29, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2021-37415

Published: 2021-12-01
Last revised: 2021-12-01
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2021-12-01 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; EPSS first scored at 99.9%
2026-07-28 EPSS 99.9% to 99.8%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2021-12-15 (past due).

Apply updates per vendor instructions.

Official fix for CVE-2021-37415

The authoritative fix and affected-version list are published by the vendor. Find the ManageEngine ServiceDesk Plus (SDP) advisory on Zoho ManageEngine Security Advisories.

Zoho ManageEngine Security Advisories CISA KEV entry

Common questions about CVE-2021-37415

Is CVE-2021-37415 actively exploited?

Yes. CVE-2021-37415 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-12-01, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 100%.

What is the CISA deadline and required action for CVE-2021-37415?

CISA set the federal (BOD 22-01) remediation due date at 2021-12-15, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.

What fixes CVE-2021-37415?

The authoritative fix is in the vendor advisory: see Zoho ManageEngine Security Advisories for the patched ManageEngine ServiceDesk Plus (SDP) versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2021-37415?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2021-37415's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Zoho CVEs: CVE-2022-28810 CVE-2022-47966 CVE-2022-35405 CVE-2021-44515 CVE-2021-44077 CVE-2020-10189 CVE-2021-40539 CVE-2019-8394
All Zoho exploited CVEs on one page: Zoho vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.