CVE-2021-27855Public exploitNetwork attack vector

Read-only-to-administrator escalation via unchecked privilege parameter

Published Dec 15, 2021 · Updated Sep 17, 2024

Missing authorization in FatPipe WARP, IPVPN, and MPVPN allows remote authenticated users with read-only access to become administrators. The userServlet account-edit operation accepts a userList JSON object with privilege set to 1 without verifying authorization to assign that role. A valid read-only account and web-management access are required; 10.1 releases before 10.1.2r60p91 and 10.2 releases before 10.2.2r42 are affected.

CVSS severity8.8
High
EPSS probability1.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Missing authorization in FatPipe WARP, IPVPN, and MPVPN allows remote authenticated users with read-only access to become administrators. The userServlet account-edit operation accepts a userList JSON object with privilege set to 1 without verifying authorization to assign that role. A valid read-only account and web-management access are required; 10.1 releases before 10.1.2r60p91 and 10.2 releases before 10.2.2r42 are affected.

The record

CVE
CVE-2021-27855
Published
Dec 15, 2021
Updated
Sep 17, 2024
Vendor
FatPipe
Product
MPVPN
Classifications
CWE-862, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.1 <10.1.2r60p91
  2. Affected versionversion=10.2 <10.2.2r42

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FatPipe · MPVPNversion=10.1 <10.1.2r60p91; version=10.2 <10.2.2r42
FatPipe · IPVPNversion=10.1 <10.1.2r60p91; version=10.2 <10.2.2r42
FatPipe · WARPversion=10.1 <10.1.2r60p91; version=10.2 <10.2.2r42

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8CERT/CCCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1098Account Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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