8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.3 High
AI Score
Confidence
High
6.5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:P/I:P/A:P
0.002 Low
EPSS
Percentile
53.9%
Successful exploitation of this vulnerability could allow for local privilege escalation or remote code execution through a malicious webpage.
The following versions of OpenVPN-Client are affected:
An attacker can take leverage on this architecture and send the config command from any application running on the local host machine to force the back-end server into initializing a new open-VPN instance with arbitrary open-VPN configuration. This could result in the attacker achieving execution with privileges of a SYSTEM user.
CVE-2021-27406 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
Sharon Brizinov of Claroty reported this vulnerability to CISA.
PerFact has released Version 1.6.0, which mitigates this vulnerability.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-27406
cwe.mitre.org/data/definitions/15.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=PerFact%20OpenVPN-Client+https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-01
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics/alerts/ICS-ALERT-10-301-01
us-cert.cisa.gov/ics/recommended-practices
us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
www.facebook.com/CISA
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-01&title=PerFact%20OpenVPN-Client
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
www.instagram.com/cisagov
www.linkedin.com/company/cybersecurity-and-infrastructure-security-agency
www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-01
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-01
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=PerFact%20OpenVPN-Client&body=www.cisa.gov/news-events/ics-advisories/icsa-21-056-01
8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.3 High
AI Score
Confidence
High
6.5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:P/I:P/A:P
0.002 Low
EPSS
Percentile
53.9%