Security readout for executives and security teams
Plain-English summary
A remote, unauthenticated attacker can abuse vulnerable Kaseya VSA servers to run PowerShell across every managed device. This turns one management server into a distribution point for widespread compromise, including data theft, operational disruption, and malware deployment.
Executive priority
Treat as an immediate remediation and compromise-assessment priority. It combines unauthenticated remote access, enterprise-wide endpoint reach, critical impact, and confirmed exploitation. Leadership should require verified patch status and evidence that historically exposed environments were investigated.
Technical view
CVE-2018-20753 affects Kaseya VSA RMM releases before 9.3.0.35, 9.4.0.36, and 9.5.0.5 in their respective branches. Network attackers require neither privileges nor user interaction. Successful exploitation enables PowerShell payload execution on all managed endpoints. CVSS 3.1 rates it 9.8 critical.
Likely exposure
Organizations operating the specified older Kaseya VSA versions are exposed. Internet-reachable VSA servers present the clearest concern, although the bundle does not define every deployment path. The affected inventory metadata is incomplete, so confirm versions directly rather than relying only on CPE-based scanners.
Exploitation context
Attackers actively exploited this vulnerability in January 2018, and CISA lists it in the Known Exploited Vulnerabilities catalog. The cited Huntress analysis describes malicious cryptocurrency-mining activity. Current exploitation volume is not established by the provided sources.
Researcher notes
The source bundle identifies no CWE and supplies unusable affected-product metadata, but its description names Kaseya VSA RMM and fixed thresholds. CVSS indicates network reachability, low complexity, no privileges, no interaction, unchanged scope, and high confidentiality, integrity, and availability impact. Avoid inferring additional affected versions or attack mechanisms.
Mitigation direction
- Upgrade each affected VSA branch to its stated fixed version or a vendor-supported later release.
- Follow current Kaseya guidance before changing production management infrastructure.
- Restrict external access to VSA while remediation is pending.
- Investigate managed endpoints if a vulnerable VSA server was previously reachable by untrusted networks.
Validation and detection
- Inventory every Kaseya VSA server and record its exact installed version.
- Confirm versions meet or exceed 9.3.0.35, 9.4.0.36, or 9.5.0.5, as applicable.
- Review VSA and endpoint telemetry for unexpected PowerShell activity or centrally distributed tasks.
- Verify network controls prevent unnecessary untrusted access to VSA interfaces.
- Confirm endpoint investigation coverage includes every device managed during the vulnerable period.
Public sources used
The source record changed after analysis: Material source record changed after analysis.
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.
CVE-2018-20753 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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
SSVC decision data
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2018-20753 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2022-04-13T00:00:00.000Z: CVE-2018-20753 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- https://blog.huntresslabs.com/deep-dive-kaseya-vsa-mining-payload-c0ac839a0e88CVE reference, mitre · x_refsource_MISC
- https://helpdesk.kaseya.com/hc/en-gb/articles/360000333152CVE reference, mitre · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-20753CVE reference, CISA-ADP · 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.