CVE-2021-22908Public exploitNetwork attack vector

Root code execution via oversized SMB server name

Published May 27, 2021 · Updated Aug 3, 2024

Buffer overflow in Windows File Resource Profiles in Pulse Secure Pulse Connect Secure 9.x allows remote authenticated users to execute root code. The wnf.cgi endpoint passes an oversized SMB server name to the Samba-derived smbclt helper, causing a stack or heap buffer overflow. Reachability requires a valid user session and a Windows File Access policy permitting attacker-chosen SMB hosts; this policy defaults to deny from 9.1R3.

CVSS severity8.8
High
EPSS probability69.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Windows File Resource Profiles in Pulse Secure Pulse Connect Secure 9.x allows remote authenticated users to execute root code. The wnf.cgi endpoint passes an oversized SMB server name to the Samba-derived smbclt helper, causing a stack or heap buffer overflow. Reachability requires a valid user session and a Windows File Access policy permitting attacker-chosen SMB hosts; this policy defaults to deny from 9.1R3.

The record

CVE
CVE-2021-22908
Published
May 27, 2021
Updated
Aug 3, 2024
Vendor
Pulse Secure
Product
Pulse Connect Secure
Classifications
CWE-120, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=Fixed in 9.1R11.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Pulse Secure · Pulse Connect Secureversion=Fixed in 9.1R11.5

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

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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