CVE-2021-22900Known exploitationNetwork attack vector

Arbitrary file write via unrestricted archive upload

Published May 27, 2021 · Updated Oct 21, 2025

Unrestricted upload in Pulse Connect Secure before 9.1R11.4 allows remote authenticated users to write files via a crafted archive. Public advisories identify multiple unrestricted uploads through the administrator web interface but do not name the handler or the missing archive validation. Administrator access is required, and successful exploitation can place attacker-chosen files on the appliance.

CVSS severity7.2
High
EPSS probability14.15%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unrestricted upload in Pulse Connect Secure before 9.1R11.4 allows remote authenticated users to write files via a crafted archive. Public advisories identify multiple unrestricted uploads through the administrator web interface but do not name the handler or the missing archive validation. Administrator access is required, and successful exploitation can place attacker-chosen files on the appliance.

The record

CVE
CVE-2021-22900
Published
May 27, 2021
Updated
Oct 21, 2025
Vendor
Pulse Secure
Product
Pulse Connect Secure
Classifications
CWE-94, CWE-669, T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=Fixed in 9.1R11.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Pulse Secure · Pulse Connect Secureversion=Fixed in 9.1R11.4

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-669Incorrect Resource Transfer Between Spheres
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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

Reported exploitation

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo