Background exploitation KEV catalog Ransomware No authentication

CVE-2021-22893

Ivanti Pulse Connect Secure Use-After-Free Vulnerability

CheckOps priority index

8.4/10 Patch within 24 h

Severity10.0

Probability4.7

Exploitation5/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 47.2% higher than 98.8% of CVEs

CVSS 3.1 10.0 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:

Exploited for 1,826 days 03 Nov 2021

CISA due date 03 May 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 5 / 5

KEV catalog (CISA)03 Nov 2021
Exploited in EUVD (ENISA)03 Nov 2021
Used by ransomwareyes
EPSS above 10 %47.2%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.

Affected products

Pulse Connect Secure

Affected versions

PCS 9.0R3 or above, PCS 9.1R1 and above

Weaknesses (CWE)

CWE-287

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

23 Apr 2021
Published
03 Nov 2021
Exploitation reported (ENISA)
03 Nov 2021
Added to the KEV catalog
03 May 2022
CISA remediation due date
26 Sept 2026
EPSS peak: 47.2%

References

Other exploited vulnerabilities from the same vendor

CVE-2026-118527Ivanti Connect Secure Generation of Predictable Numbers or Identifiers Vulnerability
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CVE-2026-111357Ivanti Connect Secure Missing Authentication for Critical Function Vulnerability
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CVE-2026-104935Ivanti Connect Secure Authentication Bypass by Spoofing Vulnerability
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CVE-2026-10520Ivanti Sentry OS Command Injection Vulnerability
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CVE-2026-6973Ivanti Endpoint Manager Mobile (EPMM) Improper Input Validation Vulnerability
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CVE-2026-1603Ivanti Endpoint Manager (EPM) Authentication Bypass Vulnerability
8.5 · Background exploitation