CVE-2018-20753

Exp

Kaseya VSA RMM before R9.3 9.3.0.35, R9.4 before 9.4.0.36, and R9.5 before 9.5.0.5 allows unprivileged remote attackers to execute PowerShell payloads on all managed devices. In January 2018, attackers actively exploited this vulnerability in the wild.

Published: 2019-02-05 Last update: 2025-11-07 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-20753 is rated Critical Active Threat (100/100): CVSS Critical severity, with high exploitation likelihood (EPSS 47.93%, 98th percentile). CISA KEV confirms active exploitation (added 2022-04-13) affecting Kaseya / Virtual System/Server Administrator (VSA). Unauthenticated remote administrative access may be possible. EPSS rose +10.23% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2018-20753

Name: Kaseya VSA Remote Code Execution Vulnerability · CISA KEV detail

Exploit added: 2022-04-13

Action due: 2022-05-04

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2018-20753

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-20753

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 37.71% 47.93% +10.23%
2 2026-02-18 44.44% 37.71% -6.74%
3 2026-01-06 — 44.44% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-20753

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2018-20753

Affected software / configurations for CVE-2018-20753

Vendor Product Version Raw CPE
kaseya virtual_system_administrator >= 9.3, < 9.3.0.35 cpe:2.3:a:kaseya:virtual_system_administrator:*:*:*:*:*:*:*:*
kaseya virtual_system_administrator >= 9.4, < 9.4.0.36 cpe:2.3:a:kaseya:virtual_system_administrator:*:*:*:*:*:*:*:*
kaseya virtual_system_administrator >= 9.5, < 9.5.0.5 cpe:2.3:a:kaseya:virtual_system_administrator:*:*:*:*:*:*:*:*

References for CVE-2018-20753

cvelogic Threat Intelligence