How severe is CVE-2023-42659?

CVE-2023-42659 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2023-42659 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42659?

CVE-2023-42659 affects Progress Ws Ftp Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-42659?

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

When was CVE-2023-42659 published?

CVE-2023-42659 was published on 2023-11-07 and last updated on 2026-06-17.

CVE-2023-42659

CVE-2023-42659 is a critical-severity vulnerability in Progress Ws Ftp Server with a CVSS 3.x base score of 9.1. 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-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Progress Ws Ftp Server
Published: 2023-11-07
Last modified: 2026-06-17

Description

In WS_FTP Server versions prior to 8.7.6 and 8.8.4, an unrestricted file upload flaw has been identified. An authenticated Ad Hoc Transfer user has the ability to craft an API call which allows them to upload a file to a specified location on the underlying operating system hosting the WS_FTP Server application.

Frequently asked questions

What is CVE-2023-42659?: In WS_FTP Server versions prior to 8.7.6 and 8.8.4, an unrestricted file upload flaw has been identified. An authenticated Ad Hoc Transfer user has the ability to craft an API call which allows them to upload a file to a specified location on the underlying operating system hosting the WS_FTP Server application.
How severe is CVE-2023-42659?: CVE-2023-42659 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2023-42659 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42659?: CVE-2023-42659 affects Progress Ws Ftp Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-42659?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-42659 published?: CVE-2023-42659 was published on 2023-11-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:progress:ws_ftp_server:*:*:*:*:*:*:*:*

More vulnerabilities in Progress Ws Ftp Server

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CVE-2023-40047 — High (CVSS 8.3): In WS_FTP Server version prior to 8.8.2, a stored cross-site scripting (XSS) vulnerability exists in WS_FTP Server's…
CVE-2023-40045 — High (CVSS 8.3): In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a reflected cross-site scripting (XSS) vulnerability exists in…
CVE-2023-40046 — High (CVSS 8.2): In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a SQL injection vulnerability exists in the WS_FTP Server manager…

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