CVE-2021-44077

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus. For every flaw being used in attacks, see Exploited flaws; for Zoho’s, see Zoho flaws being used in attacks.

CVE-2021-44077 is a security flaw in Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus, Zoho’s IT management software. Attackers can run their own code on Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 1 Dec 2021.[1]

Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Zoho has published a fix or advice.

Description

CISA calls it a manageEngine serviceDesk plus remote code execution in Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus. In its words: “Zoho ManageEngine ServiceDesk Plus before 11306, ServiceDesk Plus MSP before 10530, and SupportCenter Plus before 11014 are vulnerable to unauthenticated remote code execution”[1]

The CVE record adds: “Zoho ManageEngine ServiceDesk Plus before 11306, ServiceDesk Plus MSP before 10530, and SupportCenter Plus before 11014 are vulnerable to unauthenticated remote code execution. This is related to /RestAPI URLs in a servlet, and ImportTechnicians in the Struts configuration.”[2]

The underlying weakness is missing authentication (CWE-306), in MITRE’s list of common software weaknesses.

It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; Zoho’s advisory has them[3]. CISA names the product as Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus.

Most families won’t have Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 1 Dec 2021, 2 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Dec 2021 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 93%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as automatable: attackers can run it against many targets at once.

CISA doesn’t say who was attacked, or how.

Fix

Zoho has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]

  1. Check whether you use it.Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
  2. Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 15 Dec 2021 to fix it.
  3. If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.

You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 93%.[4]

See also

Other Zoho flaws

  • CVE-2022-28810, Zoho ManageEngine: aDSelfService plus remote code execution ·
  • CVE-2022-47966, Zoho ManageEngine: multiple products remote code execution ·
  • CVE-2022-35405, Zoho ManageEngine: multiple products remote code execution ·
  • CVE-2021-44515, Zoho Desktop Central: authentication bypass ·
  • CVE-2021-37415, Zoho ManageEngine ServiceDesk Plus (SDP): manageEngine serviceDesk authentication bypass ·

Other missing authentication flaws

  • CVE-2026-111357, Ivanti Connect Secure: missing authentication for critical function ·
  • CVE-2026-67277, MikroTik RouterOS: missing authentication for critical function ·
  • CVE-2026-81578, PaperCut NG/MF: missing authentication for critical function ·
  • CVE-2026-72529, TrueConf Server: missing authentication for critical function ·
  • CVE-2026-56164, Microsoft SharePoint Server: missing authentication for critical function ·

Added the same day

  • CVE-2021-40438, Apache: HTTP server-side request forgery (SSRF) ·
  • CVE-2021-37415, Zoho ManageEngine ServiceDesk Plus (SDP): manageEngine serviceDesk authentication bypass ·
  • CVE-2020-11261, Qualcomm Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables: multiple chipsets improper input validation ·
  • CVE-2018-14847, MikroTik RouterOS: router OS directory traversal ·

Every Zoho flaw on CISA’s list · Everything added in December 2021

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “Zoho ManageEngine ServiceDesk Plus Remote Code Execution Vulnerability”. Known Exploited Vulnerabilities Catalog, added 1 Dec 2021.
  2. ^ National Institute of Standards and Technology. “CVE-2021-44077 Detail”. National Vulnerability Database, published 29 Nov 2021.
  3. ^ Zoho. Advisories and fixes: pitstop.manageengine.com, pitstop.manageengine.com, pitstop.manageengine.com, pitstop.manageengine.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.933, percentile 99.8, 31 Oct 2026.
  5. CVE Program. “CVE-2021-44077”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.