How severe is CVE-2021-22894?

CVE-2021-22894 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-22894?

Affected package information for CVE-2021-22894 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-22894?

No fixed version has been published for CVE-2021-22894 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-22894 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2021-22894, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-22894?

CVE-2021-22894 has an EPSS (Exploit Prediction Scoring System) score of 42.0%, placing it in the 98th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2021-22894 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-22894 (Ivanti Pulse Connect Secure Collaboration Suite Buffer Overflow Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-22894?

CVE-2021-22894 is classified as Code Injection (CWE-94), Buffer Overflow (CWE-119). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2021-22894?

CVE-2021-22894 affects ivanti connect secure (2 versions, e.g. 9.0, 9.1). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2021-22894 published, and has it been updated?

CVE-2021-22894 was published on May 27, 2021 and was last updated on December 18, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03

CVE-2021-22894

HIGH

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.

Published

May 27, 2021

Updated

Dec 18, 2025

Affected

0 pkgs

Patched

None yet

Exploits

2 known

EPSS Exploitation Probability

via FIRST.org ↗

42.0%probability of exploitation in next 30 days

High Risk98th percentile+14.74%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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.

Affected Products

1 product · 40 configurations

Application

connect secureivanti

2 versions

9.09.1

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

A buffer overflow vulnerability exists in Pulse Connect Secure before 9.…

cisa.govCISANov 2021

A buffer overflow vulnerability exists in Pulse Connect Secure before 9.…

tenable.comAPIApr 2021

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2021-22894 in your stack?

O3 detects CVE-2021-22894 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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