Cyber Resilience

CVE-2021-22900

RCE in Ivanti Connect Secure 9.0 … 9.1

CISA KEVActive ExploitationEUVD ExploitedRCE
Published
27 May 2021
Modified
18 December 2025
KEV Added
03 November 2021
Patch / advisory
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.14 96th percentile
Risk Priority 79 floored blend · peak EPSS

Summary

CVE-2021-22900 is a high-severity Code Injection (CWE-94) vulnerability in Ivanti Connect Secure. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Escape to Host (T1611); ranked in the top 4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2021-22900 is an unrestricted file upload vulnerability in Pulse Connect Secure versions prior to 9.1R11.4. It resides in the administrator web interface and permits an authenticated administrator to upload a maliciously crafted archive that results in arbitrary file writes on the appliance. The flaw is tracked under CWE-94 (Improper Control of Generation of Code) and CWE-669 (Incorrect Resource Transfer Between Spheres) and carries a CVSS 3.1 base score of 7.2.

An attacker who already possesses valid administrator credentials can exploit the issue over the network by submitting the crafted archive through the management interface. Successful exploitation grants the ability to write arbitrary files, which can be leveraged to achieve full control over confidentiality, integrity, and availability of the affected system.

The vendor advisory SA44784 states that the issue is resolved in Pulse Connect Secure 9.1R11.4 and later releases; administrators are advised to apply the update. The vulnerability is also listed in CISA’s Known Exploited Vulnerabilities catalog, confirming observed in-the-wild exploitation.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability allowed multiple unrestricted uploads in Pulse Connect Secure before 9.1R11.4 that could lead to an authenticated administrator to perform a file write via a maliciously crafted archive upload in the administrator web interface.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1611 Escape to Host Privilege Escalation
Adversaries may break out of a container or virtualized environment to gain access to the underlying host.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2020-8218Same product: Ivanti Connect Secureboth on KEV
CVE-2021-22894Same product: Ivanti Connect Secureboth on KEV
CVE-2020-8243Same product: Ivanti Connect Secureboth on KEV
CVE-2021-22908Same product: Ivanti Connect Secure
CVE-2019-11539Same product: Ivanti Connect Secureboth on KEV
CVE-2021-22899Same product: Ivanti Connect Secureboth on KEV
CVE-2021-22893Same product: Ivanti Connect Secureboth on KEV
CVE-2020-8260Same product: Ivanti Connect Secureboth on KEV
CVE-2024-10644Same product: Ivanti Connect Secure
CVE-2019-11510Same product: Ivanti Connect Secureboth on KEV

Affected Assets

ivanti
connect secure
9.0, 9.1
pulsesecure
pulse connect secure
≤ 9.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.3.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-669

Enforces proper authorization rules for any resource or data transfer between different spheres.

addresses: CWE-669

Accountability, documentation, and protection requirements ensure correct transfer of media resources between spheres.

addresses: CWE-669

Reduces incorrect transfers between spheres by establishing clear, separate domains for different sensitivities or functions.

addresses: CWE-94

Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.

addresses: CWE-94

Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.

addresses: CWE-669

It governs all resource transfers between spheres, preventing incorrect or unauthorized movement of data or capabilities across domain interfaces.

addresses: CWE-94

Validates inputs used in dynamic code generation to block injected directives.

addresses: CWE-94

Directly prevents execution of attacker-supplied code written into data memory regions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

Least-privilege authorization policies directly constrain resource transfers across security domains.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

PR.DS-02 partial match
prevents

Protecting data-in-transit can limit exposure during inter-sphere transfers but does not address control-flow or authorization errors.

PR.IR-01 partial match
prevents

Logical segmentation and access controls reduce unintended cross-sphere resource movement.

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Environment separation limits unintended resource leakage between spheres.

degrades

Information-transfer rules can prevent improper resource hand-off between spheres.

degrades

Access-control policies limit unintended control over transferred resources.

degrades

Managing access rights reduces risk of unauthorized resource transfer.

mitigates

Network-security controls can block improper cross-sphere transfers.

mitigates

Network segregation directly limits unintended resource movement between spheres.

References