CVE-2021-22893: Ivanti Pulse Connect Secure Use-After-Free Vulnerability

CISA Known Exploited Vulnerabilities

Name

Ivanti Pulse Connect Secure Use-After-Free Vulnerability

Vendor

Ivanti

Product

Pulse Connect Secure

Added to the catalog

2021-11-03

Due date for US federal agencies

2022-05-03

Weaknesses

CWE-287

Catalog version

2026.10.30

Ivanti Pulse Connect Secure contains a use-after-free vulnerability that allow a remote, unauthenticated attacker to execute code via license services.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA marks this vulnerability as known to be used in ransomware campaigns. CISA does not say which group used it.

Links in CISA's notes

• https://www.cisa.gov/news-events/directives/ed-21-03-mitigate-pulse-connect-secure-product-vulnerabilities)
• https://nvd.nist.gov/vuln/detail/CVE-2021-22893

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2021-04-23T17:15:08.127

Last modified

2026-08-12T05:17:37.347

Weaknesses

CWE-287, CWE-416

Pulse Connect Secure 9.0R3/9.1R1 and higher is vulnerable to an authentication bypass vulnerability exposed by the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure that can allow an unauthenticated user to perform remote arbitrary code execution on the Pulse Connect Secure gateway. This vulnerability has been exploited in the wild.

References

• https://blog.pulsesecure.net/pulse-connect-secure-security-update/ (Vendor Advisory)
• https://kb.cert.org/vuls/id/213092 (Third Party Advisory, US Government Resource)
• https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/ (Broken Link, Vendor Advisory)
• https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html (Third Party Advisory)
• https://blog.pulsesecure.net/pulse-connect-secure-security-update/ (Vendor Advisory)
• https://kb.cert.org/vuls/id/213092 (Third Party Advisory, US Government Resource)
• https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/ (Broken Link, Vendor Advisory)
• https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html (Third Party Advisory)
• https://www.kb.cert.org/vuls/id/213092 (US Government Resource)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22893 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-22893

CVE record

Assigner

hackerone

State

PUBLISHED

Published

2021-04-23T16:29:43.000Z

Updated

2026-08-12T03:55:19.358Z

Problem types

Improper Authentication - Generic (CWE-287)

Pulse Connect Secure 9.0R3/9.1R1 and higher is vulnerable to an authentication bypass vulnerability exposed by the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure that can allow an unauthenticated user to perform remote arbitrary code execution on the Pulse Connect Secure gateway. This vulnerability has been exploited in the wild.

References

• https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/
• https://blog.pulsesecure.net/pulse-connect-secure-security-update/
• https://www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html
• https://kb.cert.org/vuls/id/213092

Read on 2026-11-03T01:06:23.726Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/22xxx/CVE-2021-22893.json

Detection rules (SigmaHQ)

SigmaHQ rules whose own tags name this CVE. Each rule page shows the rule as its author published it.

• Pulse Connect Secure RCE Attack CVE-2021-22893 (status stable, level high)

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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