How severe is CVE-2021-20517?

CVE-2021-20517 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20517 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20517?

CVE-2021-20517 affects Ibm Websphere Application Server Nd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20517?

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-2021-20517 published?

CVE-2021-20517 was published on 2021-06-07 and last updated on 2026-06-17.

CVE-2021-20517

CVE-2021-20517 is a high-severity vulnerability in Ibm Websphere Application Server Nd with a CVSS 3.x base score of 8.8. 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-22.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Ibm Websphere Application Server Nd
Published: 2021-06-07
Last modified: 2026-06-17

Description

IBM WebSphere Application Server Network Deployment 8.5 and 9.0 could allow a remote authenticated attacker to traverse directories. An attacker could send a specially-crafted URL request containing "dot dot" sequences (/../) to read and delete arbitrary files on the system. IBM X-Force ID: 198435.

Frequently asked questions

What is CVE-2021-20517?: IBM WebSphere Application Server Network Deployment 8.5 and 9.0 could allow a remote authenticated attacker to traverse directories. An attacker could send a specially-crafted URL request containing "dot dot" sequences (/../) to read and delete arbitrary files on the system. IBM X-Force ID: 198435.
How severe is CVE-2021-20517?: CVE-2021-20517 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20517 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20517?: CVE-2021-20517 affects Ibm Websphere Application Server Nd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20517?: 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-2021-20517 published?: CVE-2021-20517 was published on 2021-06-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ibm:websphere_application_server_nd:*:*:*:*:*:*:*:*

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