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Known exploited vulnerability

CVE-2021-30116

criticalCVSS 3.1 9.8In CISA KEVRansomwareEPSS 86%Published · n/a

The short answer

CVE-2021-30116 affects n/a n/a and is rated critical (CVSS 9.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first.

What it is

Kaseya VSA before 9.5.7 allows credential disclosure, as exploited in the wild in July 2021. By default Kaseya VSA on premise offers a download page where the clients for the installation can be downloaded. The default URL for this page is https://x.x.x.x/dl.asp When an attacker download a client for Windows and installs it, the file KaseyaD.ini is generated (C:\Program Files (x86)\Kaseya\XXXXXXXXXX\KaseyaD.ini) which contains an Agent_Guid and AgentPassword This Agent_Guid and AgentPassword can be used to log in on dl.asp (https://x.x.x.x/dl.asp?un=840997037507813&pw=113cc622839a4077a84837485ced6b93e440bf66d44057713cb2f95e503a06d9) This request authenticates the client and returns a sessionId cookie that can be used in subsequent attacks to bypass authentication. Security issues discovered --- * Unauthenticated download page leaks credentials * Credentials of agent software can be used to obtain a sessionId (cookie) that can be used for services not intended for use by agents * dl.asp accepts credentials via a GET request * Access to KaseyaD.ini gives an attacker access to sufficient information to penetrate the Kaseya installation and its clients. Impact --- Via the page /dl.asp enough information can be obtained to give an attacker a sessionId that can be used to execute further (semi-authenticated) attacks against the system.

Weakness: CWE-522.

Severity

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploited (CISA KEV)

Yes, since Nov 3, 2021

Federal due date Nov 17, 2021

EPSS, next 30 days

86%

Higher than 100% of scored CVEs

How it can be exploited

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

What CISA says to do

Apply updates per vendor instructions.

Affected products

n/a. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2021-30116 being exploited?

Yes. CISA added CVE-2021-30116 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2021-11-17. CISA lists it as used in ransomware campaigns.

How do I fix CVE-2021-30116?

CISA's required action: Apply updates per vendor instructions.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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