How severe is CVE-2021-30640?

CVE-2021-30640 has a CVSS 3.x base score of 6.5, 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 high, and availability none.

Is CVE-2021-30640 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30640?

CVE-2021-30640 primarily affects Apache Tomcat. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30640?

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

When was CVE-2021-30640 published?

CVE-2021-30640 was published on 2021-07-12 and last updated on 2026-06-17.

CVE-2021-30640

CVE-2021-30640 is a medium-severity vulnerability in Apache Tomcat with a CVSS 3.x base score of 6.5. 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-116.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 5.8
EPSS exploit prediction: 10% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-116
Affected product: Apache Tomcat
Published: 2021-07-12
Last modified: 2026-06-17

Description

A vulnerability in the JNDI Realm of Apache Tomcat allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. This issue affects Apache Tomcat 10.0.0-M1 to 10.0.5; 9.0.0.M1 to 9.0.45; 8.5.0 to 8.5.65.

Frequently asked questions

What is CVE-2021-30640?: A vulnerability in the JNDI Realm of Apache Tomcat allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. This issue affects Apache Tomcat 10.0.0-M1 to 10.0.5; 9.0.0.M1 to 9.0.45; 8.5.0 to 8.5.65.
How severe is CVE-2021-30640?: CVE-2021-30640 has a CVSS 3.x base score of 6.5, 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 high, and availability none.
Is CVE-2021-30640 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30640?: CVE-2021-30640 primarily affects Apache Tomcat. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30640?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30640 published?: CVE-2021-30640 was published on 2021-07-12 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.14.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_diameter_signaling_router:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_pricing_design_center:12.0.0.3.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:hospitality_cruise_shipboard_property_management_system:20.1.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:tekelec_platform_distribution:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

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