Security readout for executives and security teams
Plain-English summary
CVE-2021-22900 affects Pulse Connect Secure before 9.1R11.4. An authenticated administrator could upload a malicious archive through the admin web interface and write files unexpectedly. Because CISA lists it in KEV, treat unpatched systems as exposed to real-world exploitation risk despite the need for administrator privileges.
Executive priority
Prioritize remediation for any remaining Pulse Connect Secure deployment. KEV status makes this more than a theoretical issue, and compromise of VPN infrastructure can affect remote access, identity trust, and incident response scope.
Technical view
The issue is an unrestricted archive upload/file-write flaw in the Pulse Connect Secure administrator web interface. CVSS 3.1 is 7.2: network reachable, low complexity, high privileges required, no user interaction, with high confidentiality, integrity, and availability impact. Sources identify 9.1R11.4 as the fixed release.
Likely exposure
Organizations running Pulse Connect Secure versions before 9.1R11.4 are the likely exposure group, especially where the administrator interface is reachable from untrusted networks or administrator credentials may be compromised.
Exploitation context
CISA KEV inclusion supports known exploitation. The provided sources do not describe exploit methods, campaigns, or current volume. The privilege requirement means attacker access to an administrator account or session is a major prerequisite.
Researcher notes
Evidence supports a high-impact authenticated admin file-write path via malicious archive upload. The provided bundle does not include detailed affected build ranges beyond before/fixed in 9.1R11.4, exploit indicators, or workaround specifics; rely on vendor guidance for operational details.
Mitigation direction
- Upgrade Pulse Connect Secure to 9.1R11.4 or later.
- Review the Pulse Secure advisory for vendor-specific remediation details.
- Restrict administrator interface access to trusted management networks.
- Audit administrator accounts, MFA, and recent credential compromise signals.
- Investigate suspicious archive uploads and unexpected file changes.
Validation and detection
- Inventory all Pulse Connect Secure appliances and record versions.
- Confirm each appliance is running 9.1R11.4 or later.
- Verify admin interfaces are not broadly internet-accessible.
- Review admin web logs for unusual archive upload activity.
- Check file integrity and configuration changes around suspected activity windows.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-22900 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.2 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H1.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/?kA23Z000000boUWSAYCVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22900CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.