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Full vulnerability report · 2021
CVE-2021-22894High confidence

Ivanti Pulse Connect Secure Collaboration Suite Buffer Overflow Vulnerability

Ivanti · Pulse Connect Secure

8.8HighCVSS 3.1
Recommended action
Mitigate now

CISA confirms exploitation in the wild and lists 2022-05-03 as the remediation due date.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 3 Nov 2021

Evidence used

  • CISA confirms exploitation in the wild.
  • EPSS is 41.28% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Ivanti Pulse Connect Secure and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-10026

CISA KEV mirrored by ENISA

A buffer overflow vulnerability exists in Pulse Connect Secure before 9.1R11.4 allows a remote authenticated attacker to execute arbitrary code as the root user via maliciously crafted meeting room.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 3 Nov 2021. Evidence sources: cisa_kev.
ENISA score
8.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionMitigate now

CISA confirms exploitation in the wild and lists 2022-05-03 as the remediation due date.

Mitigation available
01

What, why and how

Ivanti Pulse Connect Secure Collaboration Suite contains a buffer overflow vulnerabilities that allows a remote authenticated users to execute code as the root user via maliciously crafted meeting room.

What

Ivanti Pulse Connect Secure Collaboration Suite contains a buffer overflow vulnerabilities that allows a remote authenticated users to execute code as the root user via maliciously crafted meeting room.

Why

Untrusted data can cross into a code-evaluation path and be interpreted as executable instructions.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

What

Ivanti Pulse Connect Secure Collaboration Suite contains a buffer overflow vulnerabilities that allows a remote authenticated users to execute code as the root user via maliciously crafted meeting room.

Why

Untrusted data can cross into a code-evaluation path and be interpreted as executable instructions.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2021-11-03.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Control of Generation of Code ('Code Injection') → execute code or commands in the affected security context
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-94 ↗

CWE-94: Improper Control of Generation of Code ('Code Injection'). The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-94CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2021-10026Known-exploited evidence recorded

A buffer overflow vulnerability exists in Pulse Connect Secure before 9.1R11.4 allows a remote authenticated attacker to execute arbitrary code as the root user via maliciously crafted meeting room.

Official EUVD record ↗
Canadian Centre for Cyber Security · English · AL21-008Active Exploitation of Pulse Connect Secure Vulnerabilities - update 1

On 20 April 2021, Pulse Secure released a Security Advisory highlighting a critical remote code execution vulnerability in its Pulse Connect Secure product. Open-source reporting has indicated that active exploitation of this vulnerability as well as prior Pulse Secure vulnerabilities have been observed.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20210602Security Bulletin 02 Jun 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 02 Jun 2021, published on 2 June 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-335Multiples vulnérabilités dans Pulse Connect Secure

De multiples vulnérabilités ont été découvertes dans Pulse Connect Secure. Elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-007384Pulse Connect Secure におけるバッファエラーの脆弱性

Pulse Connect Secure には、バッファエラーの脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
Pulse Connect Secure: Fixed version 9.1R11.4
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
The Cyber Centre encourages those organizations leveraging PCS devices to: UPDATE: Apply necessary patches, Review the indicators of compromise, published by Mandiant to identify signs of compromise, [ 4 ] Check the integrity of your PCS file system with the PCS Integrity Tool. Should activity matching the content of this Alert be discovered, recipients are encouraged to contact the Cyber Centre by email ( contact@cyber.gc.ca ) or by telephone ( 1-833-CYBER-88 or 1-833-292-3788 ).
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 27 May 2021 · Last source change 21 Oct 2025, 23:25 UTC · CWE-94 · Improper Control of Generation of Code ('Code Injection')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-10026
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/active-exploitation-pulse-connect-secure-vulnerabilities.
    Before
    remediation: cyber.gc.ca/active-exploitation-pulse-connect-secure-vulnerabilities · vendor advisory: kb.pulsesecure.net/SA44784?kA23Z000000boUWSAY
    After
    vendor advisory: kb.pulsesecure.net/SA44784?kA23Z000000boUWSAY
    kb.pulsesecure.net ↗
  2. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    kb.pulsesecure.net ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    Fixed version 9.1R11.4 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Pulse Connect Secure: Fixed version 9.1R11.4 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  4. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Canadian Centre for Cyber Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Remediation guidance recorded
ENISA EUVD · EUVD-2021-10026↗Canadian Centre for Cyber Security remediation guidance↗CISA KEV record↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-22894 · cve.blacktree.nl