How severe is CVE-2021-38555?

CVE-2021-38555 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-38555 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38555?

CVE-2021-38555 affects Apache Any23. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-38555?

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-2021-38555 published?

CVE-2021-38555 was published on 2021-09-11 and last updated on 2026-06-17.

CVE-2021-38555

CVE-2021-38555 is a critical-severity vulnerability in Apache Any23 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-611.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-611
Affected product: Apache Any23
Published: 2021-09-11
Last modified: 2026-06-17

Description

An XML external entity (XXE) injection vulnerability was discovered in the Any23 StreamUtils.java file and is known to affect Any23 versions < 2.5. XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application's processing of XML data. It often allows an attacker to view files on the application server filesystem, and to interact with any back-end or external systems that the application itself can access.

Frequently asked questions

What is CVE-2021-38555?: An XML external entity (XXE) injection vulnerability was discovered in the Any23 StreamUtils.java file and is known to affect Any23 versions < 2.5. XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application's processing of XML data. It often allows an attacker to view files on the application server filesystem, and to interact with any back-end or external systems that the application itself can access.
How severe is CVE-2021-38555?: CVE-2021-38555 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-38555 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38555?: CVE-2021-38555 affects Apache Any23. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-38555?: 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-2021-38555 published?: CVE-2021-38555 was published on 2021-09-11 and last updated on 2026-06-17.

References

https://lists.apache.org/thread.html/r589d1a9f94dbeee7a0f5dbe8513a0e300dfe669bd964ba2fbfe28e07%40%3Cannounce.apache.org%3E

Affected products (1)

cpe:2.3:a:apache:any23:*:*:*:*:*:*:*:*

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CVE-2019-14678 — Critical (CVSS 10.0): SAS XML Mapper 9.45 has an XML External Entity (XXE) vulnerability that can be leveraged by malicious attackers in…
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CVE-2018-1000838 — Critical (CVSS 10.0): autopsy version <= 4.9.0 contains a XML External Entity (XXE) vulnerability in CaseMetadata XML Parser that can result…
CVE-2018-1000837 — Critical (CVSS 10.0): UML Designer version <= 8.0.0 contains a XML External Entity (XXE) vulnerability in XML parser for plugins that can…
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