OSIsoft PI Web API

published 2021-11-18 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-30478

cvss: 6.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits: 0; none known

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-313-06 updated 2021-11-09 cvss 6.9

OSIsoft PI Web API

OSIsoft LLC PI Web API <= 2019 SPI
affected: mitigation “OSIsoft recommends upgrading to PI Web API 2021. Additional information can be found in the OSIsoft PI Web API security bulletin (registration required).” customers.osisoft.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
NVD	3.1	4.8	CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

OSIsoft PI Web API

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

us-cert.cisa.gov /ics/advisories/icsa-21-313-06
third-party-advisory, us-government-resource

Sources

CVE List CVE-2021-43549
NVD CVE-2021-43549

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary