Unauthenticated credential leak and business logic flaw in Kaseya VSA <= v9.5.6
CVE-2021-30116

9.8CRITICAL

Key Information:

Vendor

Kaseya

Status
Vsa Agent
Vsa Server
Vendor
CVE Published:
9 July 2021

Badges

💰 Ransomware👾 Exploit Exists🟣 EPSS 49%🦅 CISA Reported

What is CVE-2021-30116?

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.

CISA has reported CVE-2021-30116

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed CVE-2021-30116 as being exploited and is known by the CISA as enabling ransomware campaigns.

The CISA's recommendation is: Apply updates per vendor instructions.

Human OS v1.0:
Ageing Is an Unpatched Zero-Day Vulnerability.

Remediate biological technical debt. Prime Ageing uses 95% high-purity SIRT6 activation to maintain genomic integrity and bolster systemic resilience.

Deploy the Patch

References

https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/
https://helpdesk.kaseya.com/hc/en-gb/articles/44034406846...
https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/

EPSS Score

49% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 💰

    Used in Ransomware

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

Credit

Discovered by Wietse Boonstra of DIVD
Additional research by Frank Breedijk of DIVD
JSON
.