How severe is CVE-2021-3688?

CVE-2021-3688 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-3688 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3688?

CVE-2021-3688 primarily affects Redhat Jboss Core Services Httpd. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3688?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3688 published?

CVE-2021-3688 was published on 2022-08-26 and last updated on 2026-06-17.

CVE-2021-3688

CVE-2021-3688 is a medium-severity vulnerability in Redhat Jboss Core Services Httpd with a CVSS 3.x base score of 4.8. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Redhat Jboss Core Services Httpd
Published: 2022-08-26
Last modified: 2026-06-17

Description

A flaw was found in Red Hat JBoss Core Services HTTP Server in all versions, where it does not properly normalize the path component of a request URL contains dot-dot-semicolon(s). This flaw could allow an attacker to access unauthorized information or possibly conduct further attacks. The highest threat from this vulnerability is to data confidentiality and integrity.

Frequently asked questions

What is CVE-2021-3688?: A flaw was found in Red Hat JBoss Core Services HTTP Server in all versions, where it does not properly normalize the path component of a request URL contains dot-dot-semicolon(s). This flaw could allow an attacker to access unauthorized information or possibly conduct further attacks. The highest threat from this vulnerability is to data confidentiality and integrity.
How severe is CVE-2021-3688?: CVE-2021-3688 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-3688 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3688?: CVE-2021-3688 primarily affects Redhat Jboss Core Services Httpd. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3688?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3688 published?: CVE-2021-3688 was published on 2022-08-26 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:a:redhat:jboss_core_services_httpd:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:-:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp1:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp2:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp3:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp4:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp5:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp6:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp7:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp8:*:*:*:*:*:*
cpe:2.3:a:redhat:jboss_core_services_httpd:2.4.37:sp9:*:*:*:*:*:*

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