3.5 Low
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:S/C:N/I:P/A:N
6.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
5 Medium
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
26.1%
Successful exploitation of this vulnerability could allow a remote authenticated attacker access to sensitive information or deliver false information.
The following versions of PI Web API, a data management platform, are affected:
A remote authenticated attacker with write access to a PI Server could trick a user into interacting with a PI Web API endpoint and redirect them to a malicious website. As a result, a victim may disclose sensitive information to the attacker or be provided with false information.
CVE-2021-43549 has been assigned to this vulnerability. A CVSS v3 base score of 6.9 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N).
OSIsoft reported this vulnerability to CISA.
OSIsoft recommends upgrading to PI Web API 2021. Additional information can be found in the OSIsoft PI Web API security bulletin (registration required).
OSIsoft recommends applying the following workaround in PI Web API to help reduce the risk:
Remove the OSIsoft.REST.Documentation.dll from the PI Web API installation directory.
OSIsoft recommends users employ the following defense measures to lower the impact of exploitation for PI Web API:
See the OSIsoft customer portal knowledge article for additional details and associated security updates (registration required).
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-12-146-01BβTargeted 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.
CISA also recommends users take the following measures to protect themselves from social engineering attacks:
No known public exploits specifically target this vulnerability.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-43549
customers.osisoft.com/s/knowledgearticle?knowledgeArticleUrl=000037517
customers.osisoft.com/s/knowledgearticle?knowledgeArticleUrl=Security-Alerts
cwe.mitre.org/data/definitions/79.html
docs.osisoft.com/
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=OSIsoft%20PI%20Web%20API+https://www.cisa.gov/news-events/ics-advisories/icsa-21-313-06
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics/recommended-practices
us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B
us-cert.cisa.gov/ncas/tips/ST04-014
us-cert.cisa.gov/sites/default/files/publications/emailscams_0905.pdf
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-21-313-06&title=OSIsoft%20PI%20Web%20API
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
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-21-313-06
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-313-06
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=OSIsoft%20PI%20Web%20API&body=www.cisa.gov/news-events/ics-advisories/icsa-21-313-06
3.5 Low
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:S/C:N/I:P/A:N
6.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
5 Medium
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
26.1%