How severe is CVE-2021-43449?

CVE-2021-43449 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-43449 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43449?

CVE-2021-43449 affects Onlyoffice Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43449?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-43449 published?

CVE-2021-43449 was published on 2023-01-23 and last updated on 2026-06-17.

CVE-2021-43449

CVE-2021-43449 is a high-severity vulnerability in Onlyoffice Server with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Onlyoffice Server
Published: 2023-01-23
Last modified: 2026-06-17

Description

ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Server-Side Request Forgery (SSRF). The document editor service can be abused to read and serve arbitrary URLs as a document.

Frequently asked questions

What is CVE-2021-43449?: ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Server-Side Request Forgery (SSRF). The document editor service can be abused to read and serve arbitrary URLs as a document.
How severe is CVE-2021-43449?: CVE-2021-43449 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-43449 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43449?: CVE-2021-43449 affects Onlyoffice Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43449?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-43449 published?: CVE-2021-43449 was published on 2023-01-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:onlyoffice:server:*:*:*:*:*:*:*:*

More vulnerabilities in Onlyoffice Server

CVE-2021-43445 — Critical (CVSS 9.8): ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. An attacker can authenticate with the…
CVE-2021-43447 — High (CVSS 7.5): ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. An authentication bypass in the…
CVE-2021-43444 — High (CVSS 7.5): ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. Signed document download URLs can be…
CVE-2021-43446 — Medium (CVSS 6.1): ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Cross Site Scripting (XSS). The "macros" feature of the…
CVE-2021-43448 — Medium (CVSS 5.3): ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Improper Input Validation. A lack of input validation can…

All CVEs affecting Onlyoffice Server →

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities

CVE-2026-69502 — Critical (CVSS 10.0): Server-side request forgery (ssrf) in Azure SQL Database allows an unauthorized attacker to elevate privileges over a…
CVE-2026-65801 — Critical (CVSS 10.0): Server-side request forgery (ssrf) in Microsoft Exchange Online allows an unauthorized attacker to elevate privileges…
CVE-2026-48331 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by a Server-Side Request Forgery (SSRF) vulnerability that could result in…
CVE-2026-54735 — Critical (CVSS 10.0): Prebid Server is an open-source solution for running real-time advertising auctions in the cloud. Prior to version…
CVE-2026-57106 — Critical (CVSS 10.0): Server-side request forgery (ssrf) in Data Quality allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-15409 — Critical (CVSS 10.0): A Server-side request forgery (SSRF) vulnerability has been identified in the SMA1000 Appliance Work Place interface. A…

Browse all CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities →