Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.33, 8.x before 8.0.0.23, 9.0 before 9.0.0.19, and 9.1 before 9.1.0.9 does not pro
Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.33, 8.x before 8.0.0.23, 9.0 before 9.0.0.19, and 9.1 before 9.1.0.9 does not properly require authentication, which allows remote attackers to bypass authentication and (1) add an administrative account via crafted request to LocalAuth/setAccount.aspx or (2) write to and execute arbitrary files via a full pathname in the PathData parameter to ConfigTab/uploader.aspx.
- Published
- Feb 17, 2020
- Updated
- Jun 16, 2026
- EPSS
- 82.1% · 100th percentile
- CWE
- CWE-287
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Report tools
Action score
64
This week
Don’t wait for the next maintenance window.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 25 / 30 · 82.1%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| kaseya | virtual system administrator | cpe:2.3:a:kaseya:virtual_system_administrator |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- kaseya virtual system administrator7.0.0.0 and later · before 7.0.0.33
- kaseya virtual system administrator8.0.0.0 and later · before 8.0.0.23
- kaseya virtual system administrator9.0.0.0 and later · before 9.0.0.19
- kaseya virtual system administrator9.1.0.0 and later · before 9.1.0.9
Same product
kaseya: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-20753Kaseya 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 PowerShelKEV78This week
- CVE-2015-6589Directory traversal vulnerability in Kaseya Virtual System Administrator (VSA) 7.0.0.0 before 7.0.0.33, 8..0.0.0 before 8.0.0.23, 9.0.0.0 be39Monitor
- CVE-2019-15506An issue was discovered in Kaseya Virtual System Administrator (VSA) through 9.4.0.37.31Monitor
- CVE-2017-12410It is possible to exploit a Time of Check & Time of Use (TOCTOU) vulnerability by winning a race condition when Kaseya Virtual System Admini29Monitor
- CVE-2015-2863Open redirect vulnerability in Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.29, 8.x before 8.0.0.18, 9.0 before 9.0.0.14, and 20Monitor
- CVE-2015-2862Directory traversal vulnerability in Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.29, 8.x before 8.0.0.18, 9.0 before 9.0.0.1419Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×2
- Exploit-DB entry ×2
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | webapps | 2015-09-29 |
| Exploit-DB entry | remote | 2015-10-05 |
| Metasploit module | auxiliary/admin/http/kaseya_master_adminKaseya VSA Master Administrator Account Creationauxiliary | 2015-09-23 |
| Metasploit module | exploit/windows/http/kaseya_uploaderKaseya VSA uploader.aspx Arbitrary File Uploadexploit | 2015-09-23 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-1609 d
- First PoC-1603 d
- Published
- TodayOct 6, 2026+2423 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-287 · Improper AuthenticationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Root cause
Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.
The bug in code
The whole CWE-287 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
app.use("/admin", requireSession, adminRouter);
// Route added later skips the middlewareapp.post("/admin-api/config", updateConfig);Fixed
const admin = express.Router();admin.use(requireSession, requireRole("admin"));
admin.post("/config", updateConfig);app.use("/admin", admin);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Authentication AbuseCAPEC-114Medium
- Authentication BypassCAPEC-115Medium
- Identity SpoofingCAPEC-151likelihood: Medium · Medium
- Fake the Source of DataCAPEC-194Medium
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- Utilizing REST's Trust in the System Resource to Obtain Sensitive DataCAPEC-57likelihood: Medium · Very High
- Session HijackingCAPEC-593likelihood: High · Very High
- Token ImpersonationCAPEC-633Medium
ATT&CK techniques
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.zerodayinitiative.com/advisories/ZDI-15-448
- www.zerodayinitiative.com/advisories/ZDI-15-449
- helpdesk.kaseya.com/entries/96164487--Kaseya-Security-Advisory
Vendor advisories and official records. Exploit/PoC links are deliberately left out.